Absorbent article which includes superabsorbent material located in discrete pockets having water-sensitive and water-insensitive containment structures

ABSTRACT

An absorbent article comprises a first, liquid-permeable carrier layer and at least a second carrier layer. A water sensitive attaching mechanism secures together the carrier layers to provide substantially attached zones and substantially unattached zones thereof. The substantially unattached zones provide a plurality of pocket regions, and a high absorbency material is located within the pocket regions to provide an absorbent laminate. A secondary attaching mechanism secures together the carrier layers along selected secondary attachment regions and provides a substantially water-insensitive connection therebetween. The secondary attachment regions are substantially restricted to locations spaced from the pocket regions.

TECHNICAL FIELD

This invention relates to absorbent articles, particularly absorbentpersonal care products. More particularly, the invention relates todisposable garments which include discrete pockets of superabsorbentpolymer material held between a pair of carrier sheets.

BACKGROUND OF THE INVENTION

Absorbent articles, such as disposable diapers, have comprised anabsorbent pad assembly having an absorbent pad and pockets for retaininga hydrocolloid material in association with the pad. For example, seeU.S. Pat. No. 4,055,180 issued Oct. 25, 1977 to H. Karami, and U.S. Pat.No. 4,360,021 issued Nov. 23, 1982 to J. Stima.

Absorbent articles have also comprised an absorbent layer having atleast one pocket containing a uniform admixture of discretesuperabsorbent particles and discrete introfying particles. For example,see U.S. Pat. No. 4,327,728 issued May 4, 1982 to R. Elias, and U.S.Pat. No. 4,381,783 issued May 3, 1983 to R. Elias.

Other absorbent articles have included a quantity of highlyliquid-sorbent superabsorbent material provided in discrete spaced-apartregions between upper and lower fibrous webs of a diaper batt, with anetwork of densified wicking embossments and at least one integraldensified wicking layer provided for promoting efficient wicking andtransport of liquid within the absorbent structure. See, for example,U.S. Pat. No. 4,960,477 issued Oct. 2, 1990 to F. Mesek.

Conventional absorbent articles, such as those described above, have notprovided adequate performance. The employed quantities of superabsorbentmaterial have not been efficiently utilized and the containment of thesuperabsorbent material during the use cycle of the article has beeninadequate. The uptake rate of absorbed liquids has been insufficient,and the absorbent articles have exhibited excessive leakage.

BRIEF DESCRIPTION OF THE INVENTION

Generally stated, the present invention provides a distinctive absorbentarticle comprising a first, liquid-permeable carrier layer and at leasta second carrier layer. A water-sensitive attaching means securestogether the carrier layers to provide substantially attached zones andsubstantially unattached zones thereof. The substantially unattachedzones provide a plurality of pocket regions, and a high absorbencymaterial is located within the pocket regions to provide an absorbentlaminate. A secondary attaching means secures together the carrierlayers along selected secondary attachment regions and provides asubstantially water-insensitive connection therebetween. The secondaryattachment regions are substantially restricted to locations spaced fromthe pocket regions.

The various aspects of the absorbent article of the invention canprovide an absorbent structure which more securely locates and containsthe high-absorbency material in a selected array of pockets when thearticle is dry. When the article becomes wetted, the absorbent structureof the invention can better maintain the location of the high-absorbencymaterial while accommodating the increased volume of the swollenmaterial. In addition, the swollen absorbent gel material is less liableto escape the confines of the absorbent laminate. At the same time, thewater-sensitivity of the attaching means can help maintain interstitialchannels between the individual pocket regions to facilitate the flow ofliquid to each of the pocket regions. The quantity of high-absorbencymaterial contained in the pocket regions of the absorbent structure canbe more efficiently utilized, and the absorption characteristics of thestructure can be improved. As a result, the absorbent article can beconfigured with a thinner structure which is capable of absorbing largeramounts of liquid and exhibits reduced leakage. The thinner structurecan in turn provide improved fit and comfort on the wearer.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood and further advantages willbecome apparent when reference is made to the following detaileddescription and accompanying drawings in which:

FIG. 1 representatively shows a partially cut-away, top plan view of afully extended article of the invention;

FIG. 2 representatively shows a length-wise, cross-sectional, side viewof the article of the invention illustrated in FIG. 1;

FIG. 3 representatively shows a perspective view of an article of theinvention wherein the various elastics have contracted to gather theelasticized sections thereof;

FIG. 4 illustrates a length-wise, cross-sectional, side view of anembodiment of a representative article of the invention having a surgelayer on the outer side surface of the topsheet;

FIG. 5 representatively shows a top view of an absorbent structure ofthe invention having an absorbent laminate located on a bodyside surfaceof a supplemental absorbent body provided by a selected distributionlayer;

FIG. 6 representatively shows a partially cut-away, top view of anabsorbent laminate of the invention;

FIG. 7 representatively shows a cross-sectional, side view of theabsorbent laminate illustrated in FIG. 6;

FIG. 8 representatively shows a cross-sectional, side view of anabsorbent structure of the invention having a distribution layerpositioned on a bodyside surface of an absorbent laminate;

FIG. 9 representatively shows the use of a heat sealing unit to formpockets regions in an absorbent laminate;

FIG. 10 representatively shows the use of an embossing die employed toform pockets regions in an absorbent laminate;

FIG. 11 representatively shows a top view of a vacuum box employed toform particular arrangements of the invention;

FIG. 12 representatively shows a partially cut-away, top plan view of anabsorbent laminate having substantially water-insensitive, secondaryattachments which extend along an entire periphery of the laminate;

FIG. 13 representatively shows a partially cut-away, top plan view of anabsorbent laminate having substantially water-insensitive, secondaryattachments which extend along the lateral, side peripheries of thelaminate, and representatively shows substantially water-insensitive,secondary attachment means located at interstitial locations betweenimmediately adjacent pocket regions; and

FIG. 14 representatively shows a cross-sectional view of a wettedabsorbent laminate wherein substantially water-insensitive secondaryattachment means have helped to maintain channel regions in the wettedlaminate.

DETAILED DESCRIPTION OF THE INVENTION

The absorbent structures of the present invention will be describedherein in relationship to their use in disposable absorbent articles,but it should be understood that potential uses of the absorbentstructures of the present invention need not be limited to disposableabsorbent articles. As used herein, the term "disposable absorbentarticle" refers to articles which absorb and contain body exudates andare intended to be discarded after a limited period of use. The articlesare not intended to be laundered or otherwise restored for reuse. Thearticles can be placed against or in proximity to the body of the wearerto absorb and contain various exudates discharged from the body. Whilethe present description will particularly be made in the context of adiaper article, it should be understood that the present invention isalso applicable to other disposable personal care absorbent articles,such as adult incontinence garments, sanitary napkins, children'straining pants, bed pads and the like.

With reference to FIGS. 1 and 2, an absorbent article, such as diaper10, is representatively shown in its extended, flat-out condition withall elastic contractions and gathers removed. The absorbent article canhave a distinctive absorbent structure, as representatively shown inFIGS. 5, 6 and 7. The absorbent structure includes a first, liquidpermeable carrier layer 98 and at least a second carrier layer 100. Awater-sensitive attaching means, such as a water-sensitive adhesive 102,secures together carrier layers 98 and 100 to provide substantiallyattached zones 104 and a multiplicity of substantially unattached zones106 thereof. The substantially unattached zones 106 provide a pluralityof pocket regions 108, and a high absorbency material, such as particlesof superabsorbent material 110, are located within pocket regions 108 toprovide an absorbent laminate 112.

In the various configurations of the invention, the attaching meansemployed to construct absorbent laminate 112 is strong enough tooperably maintain the integrity of the laminate when the laminate issubstantially dry. In addition, the attaching means has sufficientstrength to generally maintain the integrity of the laminate when thecarrier sheets have been substantially wetted with an aqueous liquid,such as urine. The holding strength of the attaching means, however, issufficiently low enough to substantially avoid excessive restriction ofthe swelling of the high absorbency material when the high absorbencymaterial is wetted to substantial saturation. Additionally, the strengthof the attaching means is sufficiently low enough to allow a separationof carrier layer 98 from carrier layer 100 under the forces of expansiongenerated by high absorbency material as the high absorbency materialabsorbs the aqueous liquid. In suitable cooperation with the strength ofthe attaching means, the carrier layers are configured to have a burststrength which is greater than the attachment strength of the attachingmeans. The selected holding strength of the attaching means and theselected, controlled separation can allow the high absorbency materialto effectively and efficiently swell in volume during the absorption ofliquid while substantially avoiding a bursting of either or both of thecarrier layers.

In FIG. 1, portions of the structure are partially cut away to moreclearly show the construction of diaper 10, and the side of the diaperwhich contacts the wearer is facing the viewer. The shown embodiment ofdiaper 10 has an intermediate crotch region 16 which interconnects thefront and rear waistband regions 12 and 14. The outer edges of thediaper define a periphery 18 in which the longitudinally extending sideedge margins are designated 20 and the laterally extending end edgemargins are designated 22. Preferably, the side edges are curvilinearand contoured to define leg openings for the diaper. The end edges areshown as straight, but optionally, may be curvilinear. The diaperadditionally has a transverse center line 24 and a longitudinal centerline 26.

Diaper 10 can include a liquid permeable topsheet 28; a substantiallyliquid impermeable backsheet 30; an absorbent body, such as an absorbentstructure 32, positioned between the topsheet and backsheet; leg elasticmembers 34; and waist elastic members 42 and 44. Topsheet 28, backsheet30, absorbent structure 32, and elastic members 34, 42 and 44 may beassembled in a variety of well-known diaper configurations.

With reference to FIGS. 4 and 5, the various aspects of the absorbentarticle of the invention can comprise an absorbent structure 32 whichincludes a retention portion 48 having a primary absorbent portion, suchas absorbent laminate 112, for storing and holding absorbed liquids,such as urine. The retention portion can also include a supplementalabsorbent, such as an outer side distribution layer 120, and inparticular aspects of the invention, the supplemental absorbent canalternatively or additionally include a bodyside distribution layer 184(FIG. 8).

The various aspects of the invention can also provide an absorbentarticle having a surge management portion 46, which may be located on abodyside surface of topsheet 28 (FIG. 2), or alternatively, may belocated on an opposite, outer side surface of the topsheet which facestoward backsheet 30 (FIG. 4). In an optional arrangement of theinvention, the surge management portion may be cooperatively arrangedwith a multi-piece topsheet. Such a topsheet configuration can, forexample, include two, individual topsheet sections which are laterallyspaced-apart from each other along the diaper cross-direction, and anintermediate surge management portion which is operatively connected tobridge therebetween. The surge management portion thereby provides themedial section of the topsheet composite assembly.

Absorbent article structures suitable for use with the present inventionare described in U.S. patent application Ser. No. 07/757,778 of D.Proxmire et al., filed Sep. 11, 1991, and entitled "ABSORBENT ARTICLEHAVING A LINER WHICH EXHIBITS IMPROVED SOFTNESS AND DRYNESS, ANDPROVIDES FOR RAPID UPTAKE OF LIQUID" (Attorney Docket No. 9932), nowU.S. Pat. No. 5,192,606 issued Mar. 9, 1993, the disclosure of which ishereby incorporated by reference to the extent that it is consistent(not contradictory) with the present specification. Other absorbentarticle structures suitable for use with the present invention aredescribed in U.S. patent application Ser. No. 07/757,760; "THINABSORBENT ARTICLE HAVING RAPID UPTAKE OF LIQUID"; of W. Hanson et al.(Attorney Docket No. 9922), the disclosure of which is herebyincorporated by reference to the extent that it is consistent herewith.

In the embodiment of diaper 10 representatively shown in FIGS. 1-3,topsheet 28 and backsheet 30 are generally coextensive and have lengthand width dimensions which are generally larger than the correspondingdimensions of absorbent structure 32. Topsheet 28 is associated with andsuperimposed on backsheet 30, thereby defining the periphery 18 ofdiaper 10. The periphery delimits the outer perimeter or the edges ofthe diaper 10, and in the illustrated embodiment, comprises end edges 22and contoured longitudinal edges 20. The diaper 10 has front and backwaistband regions 12 and 14, respectively extending from the laterallyextending end edges 22 of diaper periphery 18 toward the transversecenter line 24 of the diaper along a distance of from about 2 percent toabout 10 percent and preferably about 5 percent of the length of diaper10. The waistband regions comprise those upper portions of diaper 10,which when worn, wholly or partially cover or encircle the waist ormid-lower torso of the wearer. In particular aspects of the invention,backsheet 30 provides front and/or rear waistbands 12, 14 which aresubstantially impermeable to liquid. In other aspects of the invention,backsheet 30 can provide front and/or rear waistbands 12, 14 which aresubstantially impermeable to both liquid and air.

The intermediate, crotch region 16 lies between and interconnectswaistband regions 12 and 14, and comprises that portion of diaper 10which, when worn, is positioned between the legs of the wearer andcovers the lower torso of the wearer. Thus, the crotch region 16 is anarea where repeated fluid surges typically occur in diaper 10 or otherdisposable absorbent article.

Topsheet 28 presents a body-facing surface which is compliant,soft-feeling, and non-irritating when contacting the wearer's skin.Further, topsheet 28 can be less hydrophilic than retention portion 48,and is sufficiently porous to be liquid permeable, permitting liquid toreadily penetrate through its thickness. A suitable topsheet 28 may bemanufactured from a wide selection of web materials, such as porousfoams, reticulated foams, apertured plastic films, natural fibers (forexample, wood or cotton fibers), synthetic fibers (for example,polyester or polypropylene fibers), or a combination of natural andsynthetic fibers. Topsheet 28 is typically employed to help isolate thewearer's skin from liquids held in absorbent structure 32.

Various woven and nonwoven fabrics can be used for topsheet 28. Forexample, the topsheet may be composed of a meltblown or spunbonded webof polyolefin fibers. The topsheet may also be a bonded-carded-webcomposed of natural and synthetic fibers.

For the purposes of the present description, the term "nonwoven web"means a web of material which is formed without the aid of a textileweaving or knitting process. The term "fabrics" is used to refer to allof the woven, knitted and nonwoven fibrous webs.

The topsheet fabrics may be composed of a substantially hydrophobicmaterial, and the hydrophobic material may optionally be treated with asurfactant or otherwise processed to impart a desired level ofwettability and hydrophilicity. In a particular embodiment of theinvention, topsheet 28 is a nonwoven, spunbond polypropylene fabriccomposed of about 2.8-3.2 denier fibers formed into a web having a basisweight of about 22 gsm and density of about 0.06 gm/cc. The fabric issurface treated with about 0.28% Triton X-102 surfactant.

In the illustrated embodiment, two containment flaps 62 are connected tothe bodyside surface of topsheet layer 28. Suitable constructions andarrangements for containment flaps 62 are described, for example, inU.S. Pat. No. 4,704,116 issued Nov. 3, 1987, to K. Enloe, the disclosureof which is hereby incorporated by reference to the extent that it isconsistent herewith.

Containment flaps 62, in the shown arrangements, are attached totopsheet layer 28 along fixed edges 64 of the flaps. A movable edge 66of each containment flap includes a flap elastic member 68 comprisingone or more individual strands of elastomeric material. For example, aplurality of elastic strands may be configured in a spatially separated,generally parallel arrangement, and a suitable elastic strand can, forexample, be composed of a 470 decitex Lycra elastomer. Elastic member 68is connected to the movable edge of the containment flap in anelastically contractible condition such that the contraction of theelastic components thereof gathers and shortens the edge of thecontainment flap. As a result, the movable edge of each containment flaptends to position itself in a spaced relation away from the bodysidesurfaces of topsheet 28 and/or surge management portion 46 toward agenerally upright and approximately perpendicular configuration,especially in the crotch section of the diaper. The containment flapsmay be constructed of a material which is the same as or different thanthe material comprising topsheet 28. In optional embodiments, thecontainment flaps may be constructed of a material which is the same asor different than the material comprising surge management portion 46.The containment flaps may be composed of a material which is airpermeable, liquid permeable, substantially liquid impermeable orcombinations thereof.

Backsheet 30 may be composed of a liquid permeable material, butpreferably comprises a material which is configured to be substantiallyimpermeable to liquids. For example, a typical backsheet can bemanufactured from a thin plastic film, or other flexibleliquid-impermeable material. As used in the present specification, theterm "flexible" refers to materials which are compliant and which willreadily conform to the general shape and contours of the wearer's body.Backsheet 30 prevents the exudates contained in absorbent structure 32from wetting articles such as bedsheets and overgarments which contactdiaper 10. The backsheet may be a unitary layer of material or may be acomposite layer composed of multiple components assembled side-by-sideor laminated.

The shown embodiment of backsheet 30 includes protruding ear sectionswhich extend laterally at the waistband portions 12 and 14 of thediaper. The ear sections cooperate with the crotch section of backsheet30 to operably provide leg opening regions for positioning about thelegs of the wearer.

In particular embodiments of the invention, backsheet 30 is apolyethylene film having a thickness of from about 0.012 millimeters toabout 0.051 millimeters. In the shown embodiment, the backsheet is afilm having a thickness of about 0.032 millimeters. Alternativeconstructions of the backsheet may comprise a woven or nonwoven fibrousweb layer which has been totally or partially constructed or treated toimpart the desired levels of liquid impermeability to selected regionsthat are adjacent or proximate the absorbent body.

In a particular aspect of the invention, a terminal edge of thesubstantially liquid impermeable backsheet material extends to aposition which is substantially coterminous with a front or rearwaistband edge of the backsheet member. In the illustrated embodiment,for example, a polymer film comprising backsheet 30 extends to aposition which is substantially coterminous with a front or rearwaistband edge of the backsheet.

Backsheet 30 typically provides the outer cover of the article.Optionally, the article backsheet may comprise one or more separatelayers which are in addition to the outer cover layer and may beinterposed between the outer cover layer and the absorbent structure.

Backsheet 30 may optionally be composed of a micro-porous, "breathable"material which permits water vapor to escape from absorbent structure 32while still preventing liquid exudates from passing through thebacksheet. For example, the breathable backsheet may be composed of amicroporous polymer film or a nonwoven fabric which has been coated orotherwise treated to impart a desired level of liquid impermeability.For example, a suitable microporous film is a PMP-1 material, which isavailable from Mitsui Toatsu Chemicals, Inc., a company having officesin Tokyo, Japan; or an XKO-8044 polyolefin film available from 3MCompany of Minneapolis, Minnesota. The backsheet can also be embossed orotherwise be provided with a matte finish to exhibit a moreaesthetically pleasing appearance.

The size and shape of backsheet 30 is typically determined by the sizeof absorbent structure 32 and the exact diaper design selected. Diaper10 may, for example, have a generally T-shape, a generally I-shape or amodified hourglass shape, and can define front and/or rear ear portions38 and 40, respectively. The backsheet may extend beyond the terminaledges of absorbent structure 32 by a selected distance, such as adistance within the range of about 1.3 centimeters to 20.3 centimeters(about 0.5 to 8 inch).

Topsheet 28 and backsheet 30 are connected or otherwise associatedtogether in an operable manner. As used herein, the term "associated"encompasses configurations in which topsheet 28 is directly joined tobacksheet 30 by affixing topsheet 28 directly to backsheet 30, andconfigurations wherein topsheet 28 is joined to backsheet 30 by affixingtopsheet 28 to intermediate members which in turn are affixed tobacksheet 30. Topsheet 28 and backsheet 30 can be affixed directly toeach other in the diaper periphery 18 by attachment means (not shown)such as an adhesive, sonic bonds, thermal bonds or any other attachmentmeans known in the art. For example, a uniform continuous layer ofadhesive, a patterned layer of adhesive, a sprayed pattern of adhesiveor an array of separate lines, swirls or spots of construction adhesivemay be used to affix topsheet 28 to backsheet 30. The above-describedattachment means may also be employed to interconnect and assembletogether the other component parts of the article.

Fastening means, such as tape tab fasteners 36, are typically applied atthe lateral, side ends of the back waistband region 14 of diaper 10 toprovide a mechanism for holding the diaper on the wearer in aconventional manner. Tape tab fasteners 36 can be any of those wellknown in the art, and are typically applied to the corners of diaper 10.Suitable adhesive tape fasteners are described in U.S. Pat. No.5,147,347 issued Sep. 15, 1992 to Y. Huang et al. (Attorney Docket No.9871), the disclosure of which is hereby incorporated by reference tothe extent that it is consistent herewith.

Elastic members 34, 42 and 44 are disposed adjacent periphery 18 ofdiaper 10. Along each side edge region 20, leg elastic members 34 arearranged to draw and hold diaper 10 against the legs of the wearer.Waist elastic members, such as rear waist elastic 42, may also bedisposed adjacent either or both of the end edges 22 of diaper 10 toprovide elasticized waistbands.

The elastic members are secured to diaper 10 in an elasticallycontractible condition so that in a normal under strain configuration,the elastic members effectively contract against diaper 10. The elasticmembers can be secured in an elastically contractible condition in atleast two ways, for example, the elastic members may be stretched andsecured while diaper 10 is in an uncontracted condition. Alternatively,diaper 10 may be contracted, for example, by pleating, and the elasticmembers secured and connected to diaper 10 while the elastic members arein their relaxed or unstretched condition. Still other means, such asheat-shrink elastic material, may be used to gather the garment.

In the embodiment illustrated in FIG. 1, leg elastic members 34 extendessentially along the complete length of crotch region 16 of diaper 10.Alternatively, elastic members 34 may extend the entire length of diaper10, or any other length suitable providing the arrangement ofelastically contractible lines desired for the particular diaper design.

Elastic members 34, 42 and 44 may have any of a multitude ofconfigurations. For example, the width of the individual elastic members34 may be varied from 0.25 millimeters (0.01 inches) to 25 millimeters(1.0 inches) or more. The elastic members may comprise a single strandof elastic material, or may comprise several parallel or non-parallelstrands of elastic material, or may be applied in a rectilinear orcurvilinear arrangement. Where the strands are non-parallel, two or moreof the strands may intersect or otherwise interconnect within theelastic member. The elastic members may be affixed to the diaper in anyof several ways which are known in the art. For example, the elasticmembers may be ultrasonically bonded, heat and pressure sealed using avariety of bonding patterns, or adhesively bonded to diaper 10 withsprayed or swirled patterns of hot melt adhesive. The variousconfigurations of the invention may have the elastic members located onthe inward-most, bodyside surface of topsheet 28. Alternatively, theelastic members may be interposed between topsheet 28 and backsheet 30.

In the representatively shown embodiments of the invention, theillustrated leg elastic members 34 may comprise a carrier sheet 37 towhich are attached a grouped set of elastics composed of a plurality ofindividual elastic strands 39. The elastic strands may intersect or beinterconnected, or be entirely separated from each other. The showncarrier sheet may, for example, comprise a 0.002 cm thick film ofunembossed polypropylene material. The shown elastic strands can, forexample, be composed of Lycra® elastomer available from DuPont, abusiness having offices in Wilmington, Delaware. Each elastic strand istypically within the range of about 620-1050 decitex (dtx), and can beabout 940 dtx in an embodiment of the invention wherein three strandsare employed for each elasticized legband.

Leg elastics 34 may be generally straight or optionally curved. Forexample, the curved elastics can be inwardly bowed toward thelongitudinal centerline of the diaper with the innermost point (or apex,relative to the cross-direction of the article) of the set of curvedelastic strands positioned approximately 1.9-3.8 centimeters (about0.75-1.5 inches) inward from the outer most edge of the set of elasticstrands. In particular arrangements, the curvature of the elastics maynot be configured or positioned symmetrically relative to the lateralcenterline of the diaper. As representatively shown in FIG. 1, thecurved elastics may have an inwardly bowed and outwardly bowed,reflexed-type of curvature, and the length-wise center of the elasticsmay be offset by a selected distance within the range of about 0-8 cmtoward either the front or rear waistband of the diaper to providedesired fit and appearance. In particular embodiments of the invention,the innermost point (apex) of the set of curved elastics can be offsetabout 0-12 cm towards the front or rear waistband of the diaper, and theoutwardly bowed reflexed-portion can be positioned toward the diaperfront waistband.

The shown embodiment of the invention includes a first waist elasticmember 42 located at rear waistband portion 14 of diaper 10, and asecond waist elastic member 44 positioned at front waistband portion 12.Optional configurations of the invention, however, may include only asingle waist elastic member placed at either the front or rear waistbandof the diaper. For example, the diaper may include only one waistelastic member located along the rear diaper waistband. Waist elastic 42can be positioned in the rear end margin 22 provided by backsheet 30,and can be located in a substantially co-linear, cross-directionalalignment with the shown pair of fastener tabs 36.

The waist elastic members can have a laterally extending,cross-directional width dimension which is within the range of about20-80 percent of article width 92. Alternatively, the waist elasticwidth dimension is within the range of about 25-60 percent of articlewidth 92, and optionally, is within the range of about 40-50 percent ofthe article width. In particular aspects of the invention, waistelastics 42 and/or 44 can have a cross-directional width dimensionwithin the range of about 5-33 centimeters. Alternatively, thecross-dimensional width dimension of the waist elastic is within therange of about 10-20 centimeters, and optionally is within the range ofabout 12-16 centimeters.

A waist elastic member 42 or 44 can also have a longitudinally extendinglength dimension which is within the range of about 1-10 centimeters.Alternatively, the length dimension of the waist elastic is within therange of about 2-8 centimeters, and optionally, is within the range ofabout 2.5-5 centimeters.

The elastic members, such as waist elastics 42 and 44, can be composedof an elastomeric, cloth-like nonwoven fibrous material, such as anelastomeric stretch-bonded laminate (SBL) web or an elastomericmeltblown web. Examples of suitable meltblown elastomeric fibrous websfor forming the elastic members are described in U.S. Pat. No. No.4,663,220 issued May 5, 1987, to T. Wisneski, et al., the disclosure ofwhich is hereby incorporated by reference to the extent that it isconsistent with the present description. Examples of composite fabricscomprising at least one layer of nonwoven textile fabric secured to afibrous elastic layer are described in European Patent Application EPA 0110 010 published Apr. 8, 1987, with the inventors listed as J. Tayloret al., the disclosure of which is hereby incorporated by reference tothe extent that it is consistent herewith. The composite nonwovenfabrics are commonly referred to as stretch-bonded laminates.

In yet another aspect of the invention, the elastic members, such aswaist elastics 42 and 44, can be composed of an elastomeric, stretchablecomposite web comprising individual, discrete strips of elastomericmaterial secured to one or more nonwoven fibrous layers. Such acomposite web may, for example, comprise an elastomeric meltblownmaterial arranged in a selected pattern of strips and suitablysandwiched and attached between two layers of nonwoven, spunbondedfibrous material. The composite web may alternatively comprise aselected pattern of individual elastomeric strips operably secured to anonwoven fibrous layer or between two nonwoven layers. The elastomerstrips may, for example, be composed of a thermoplastic, melt extrudablematerial. Examples of suitable elastomer materials includepolyether-polyamide block copolymers, polyurethanes, synthetic linearA-B-A and A-B block copolymers, chlorinated rubber/EVA (ethylene-vinylacetate) blends, EPDM (ethylene-propylene diene monomer) rubbers, EPM(ethylene-propylene monomer) rubbers, blends of EPDM/EPM/EVA, and thelike.

An absorbent body, such as absorbent structure 32, is positioned betweentopsheet 28 and backsheet 30 to form diaper 10. The absorbent body has aconstruction which is generally compressible, conformable,non-irritating to the wearer's skin. It should be understood that, forpurposes of this invention, the absorbent structure may comprise asingle, integral piece of material, or alternatively, may comprise aplurality of individual separate pieces of material which are operablyassembled together. Where the absorbent structure comprises a single,substantially integral piece of material, the material could include thedesired structural features formed into selected spatial regionsthereof. Where the absorbent structure comprises multiple pieces, thepieces may be configured as discrete layers or as other nonlayeredshapes and configurations. Furthermore, the individual pieces may becoextensive or non-coextensive, depending upon the requirements of theproduct. It is preferred, however, that each of the individual pieces bearranged in an operable, intimate contact along at least a portion ofits boundary with at least one other adjacent piece of the absorbentstructure. Alternatively, each piece is connected to an adjacent portionof the absorbent structure by a suitable bonding and/or fiberentanglement mechanism, such as ultrasonic or adhesive bonding, ormechanical or hydraulic needling.

Absorbent structure 32 includes a retention portion 48 which is capableof absorbing and retaining liquid body exudates. In the embodimentillustrated by FIG. 5, for example, retention portion 48 can include anabsorbent laminate 112 which is supplemented with a distribution layer120.

Absorbent structure 32 includes a back section 51 and a front section49, and provides a liquid acquisition, target zone 53. The absorbentstructure has a contoured, curvilinear periphery, particularly along itsside edges. The two generally mirror-image, inwardly bowed, lateraledges provide for a narrower intermediate section suitable forpositioning in the crotch of the wearer.

In the representatively shown embodiment of absorbent structure 32,front section 49 can be conceptually divided into three regionscomprising two transversely spaced ear regions 50 and 52 respectively,and a central region 54.

Ear regions 50 and 52 comprise portions which generally extend from thelateral side edges of the absorbent structure toward longitudinal centerline 58 a distance from one-tenth to one-third of the overall width ofabsorbent structure 32, and connect to central region 54. When thediaper is worn, the ear regions are configured to generally engage thesides of the wearer's waist and torso, and central region 54 isconfigured to generally engage the medial portion of the wearer's waistand torso.

With respect to absorbent articles, wherein reduced bulk or reduced costmay be important, the surge management and retention portions need notextend over the entire, overall shape of the garment. In the shownaspects of the invention, for example, absorbent structure 32 caninclude a retention portion 48 which has a length 94 which is not morethan about 90 percent of article length 90. Alternatively, the retentionportion has a length 94 which is not more than about 80 percent ofarticle length 90, and optionally, has a length which is not more thanabout 70 percent of the article length to better provide desiredbenefits. In particular aspects of the invention, the retention portionhas a length 94 which is not less than about 40 percent of articlelength 90. Alternatively, the retention portion has a length 94 which isnot less than about 50 percent of article length 90, and optionally hasa length which is not less than about 60 percent of the article lengthto better provide desired performance.

In particular aspects of the invention, retention portion 48 can beasymmetrically located along the length of backsheet 30, with at leastabout 45 percent of the retention portion length 94 located in a fronthalf-section of backsheet 30. Alternatively, at least about 55 percentof the retention portion length is located in the front half-section ofbacksheet 30, and optionally, at least about 65 percent of the retentionportion length is located in the front half-section of the backsheet toprovide desired attributes.

In other aspects of the invention, a selected region of the retentionportion, such as distribution layer 120, can include a liquid-permeablewrap sheet layer 70 having a length 69 which is not more than about 50percent larger than the length of retention portion 48. Alternatively,wrap sheet length 69 is not more than about 25 percent larger than thelength of retention portion 48, and optionally, is not more than about10 percent larger than the length of the retention portion to providedesired benefits.

Retention portion 48 can be asymmetrically located along the length ofwrapsheet 70, with at least about 55 percent of the weight of theretention portion located in a front half-section of wrapsheet 70.Alternatively, at least about 65 weight percent (wt %) of the retentionportion is located in the front half-section of wrapsheet 70, andoptionally, at least about 75 wt % of the retention portion length islocated in the front half-section of the wrapsheet.

Absorbent structure 32 may be manufactured in a wide variety of sizesand shapes (for example, rectangular, trapezoidal, T-shape, I-shape,hourglass shape, etc.) and from a wide variety of materials. The sizeand the absorbent capacity of absorbent structure 32 should becompatible with the size of the intended wearer and the liquid loadingimparted by the intended use of the absorbent article. Further, the sizeand the absorbent capacity of absorbent structure 32 can be varied toaccommodate wearers ranging from infants through adults. In addition, ithas been found that with the present invention, the densities and/orbasis weights of the respective surge management 46 and retention 48portions, as well as their relative ratios, can be varied.

In a particular aspect of the invention, the absorbent structure has anabsorbent capacity of at least about 100 gm of saline. Optionally, theabsorbent capacity can be at least about 200 gm of saline.Alternatively, the absorbent structure has an absorbent capacity of atleast about 300 gm of saline, and optionally has an absorbent capacityof at least about 400 gm of saline to provide improved performance.

Various types of wettable, hydrophilic fibrous material can be used toform the component parts of absorbent structure 32. Examples of suitablefibers include naturally occurring organic fibers composed ofintrinsically wettable material, such as cellulosic fibers; syntheticfibers composed of cellulose or cellulose derivatives, such as rayonfibers; inorganic fibers composed of an inherently wettable material,such as glass fibers; synthetic fibers made from inherently wettablethermoplastic polymers, such as particular polyester or polyamidefibers; and synthetic fibers composed of a nonwettable thermoplasticpolymer, such as polypropylene fibers, which have been hydrophilized byappropriate means. The fibers may be hydrophilized, for example, bytreatment with silica, treatment with a material which has a suitablehydrophilic moiety and is not readily removable from the fiber, or bysheathing the nonwettable, hydrophobic fiber with a hydrophilic polymerduring or after the formation of the fiber. For the purposes of thepresent invention, it is contemplated that selected blends of thevarious types of fibers mentioned above may also be employed.

As used herein, the term "hydrophilic" describes fibers or the surfacesof fibers which are wetted by the aqueous liquids in contact with thefibers. The degree of wetting of the materials can, in turn, bedescribed in terms of the contact angles and the surface tensions of theliquids and materials involved. Equipment and techniques suitable formeasuring the wettability of particular fiber materials or blends offiber materials used for the surge management portion 46 can be providedby a Cahn SFA-222 Surface Force Analyzer System. When measured with thissystem, fibers having contact angles less than 90° are designated"wettable", while fibers having contact angles greater than 90° aredesignated "nonwettable".

As representatively shown in FIGS. 5-7, at least a portion of retentionportion 48 is situated in target zone 53, and can be configured tosubstantially define the boundaries of absorbent structure 32. Moreparticularly, the retention portion can comprise a first, liquidpermeable carrier layer 98 and at least a second carrier layer 100. Awater sensitive attaching means, such as a mechanism comprisingwater-sensitive adhesive 102, secures together carrier layers 98 and 100to provide substantially attached zones 104 and a multiplicity ofsubstantially unattached zones 106 thereof. The substantially unattachedzones 106 provide a plurality of pocket regions 108, and a highabsorbency material, such as particles of superabsorbent material 110,is located within pocket regions 108 to provide an absorbent laminate112.

Various techniques may be employed to construct absorbent laminate 112.For example, selected quantities of particulate superabsorbent materialmay be segregated at predetermined pocket locations of carrier layer 100and adhesive 102 may be sprayed or otherwise applied to carrier layer 98in a generalized pattern or specific localized patterns, usingconventional techniques. Carrier layer 98 can then be laminated ontocarrier layer 100 to sandwich the segregated quantities ofsuperabsorbent particles therebetween. The two carrier layers can adhereto each other at the interstitial regions between the individual pocketsand at the marginal regions around the outer periphery of the pattern ofpocket locations. The pattern of pocket locations will define thedesired pocket array, and the overall assembly can provide an operableabsorbent laminate 112.

Carrier layer 98 may be composed of a wettable or nonwettable material,and in the shown embodiment is composed of a wettable fibrous web.Suitable fibrous webs may be provided by hydraulically needled nonwovenpulp fiber webs, webs composed of cellulosic tissue, webs composed ofmeltblown fibers or the like.

A fibrous web comprising carrier layer 98 can have a basis weight withinthe range of about 5-400 gsm (grams per square meter), and desirably canhave a basis weight within the range of about 5-100 gsm. Alternatively,the basis weight can be within the range of about 10-50 gsm, andoptionally, can be within the range of about 10-30 gsm to providedesired benefits. Where carrier layer 98 comprises a fibrous syntheticpolymer web, such as a meltblown web, the fibers may be composed ofpolyethylene, polypropylene, polyester, rayon, Hydrofil®, or the like.

Second carrier layer 100 may be composed of a material which is the sameas or different than the material comprising first carrier layer 98.Second carrier layer 100 may be liquid permeable or substantially liquidimpermeable, and in the shown embodiment is liquid permeable. Inaddition, second carrier layer 100 in the illustrated embodiment iscomposed of a wettable fibrous web, but may be composed of a nonwettablefibrous web.

In the various arrangements of the invention, the carrier layers may becolored or otherwise visually highlighted to provide aesthetic benefits.For example, the sections of carrier layer material at the pocketregions of the absorbent laminate may be colored to provide visual cuesregarding the presence or performance of the distinctive aspects of theabsorbent structure.

In the illustrated embodiment, first carrier layer 98 is positionedtoward the bodyside of absorbent laminate 112, and is composed of awettable, liquid permeable, cellulosic tissue having a selected level ofwet strength and a basis weight of about 22 gsm. Similarly, secondcarrier layer 100, which is positioned toward the outer side ofabsorbent laminate 112, is composed of a wettable, liquid permeable,cellulosic tissue having a selected level of wet strength and a basisweight of about 17 gsm.

The water-sensitive attaching means for securing together carrier layers98 and 100 along attached zones 104 may comprise mechanical bonding,such as stitching, needling or the like, as well as water-sensitivethermal bonding, hydrogen bonding, adhesive bonding or the like. In theillustrated embodiment, for example, the water-sensitive carrierattachment means includes a selected pattern of water-sensitive adhesive102. Various types of water-sensitive adhesive can be configured for usein the present invention. Suitable adhesives can include, for example,National Starch 70-3998 CYCLOFLEX (a hot melt adhesive which is composedof a graft copolymer comprising a vinyl monomer, a polyalkylene oxidepolymer and a proportion of polyethylene oxide ), National Starch33-2058 (a polyvinylacetate-based latex), and the like. National Starchadhesives are available from National Starch and Chemical Co., abusiness having offices in Bridgewater, New Jersey.

For the purposes of the present description, the term, water-sensitiveattaching (or attachment) means refers to an attachment system whereinthe strength of the attachment system is great enough to adequately holdthe carrier layers 98 and 100 together when the system is substantiallydry and when the system is wet. In addition, the wet-strength of theattachment system is configured to be sufficiently low so as to notexcessively constrict the swelling expansion of the high absorbencymaterial during the absorption of liquid. The wet-strength of theattachment system is less than the separating force imparted by theswelling of the high absorbency material when the high absorbencymaterial is exposed to aqueous liquids, such as urine. In addition, thewater-sensitive attachment system is configured to release at an appliedload which is less than the load needed to delaminate thewater-sensitive attaching means without excessively tearing the materialforming either or both of the carrier layers when such layers arewetted. The water-sensitive attachment system is also configured torelease at an applied load which is less than the load needed toexcessively burst the material forming either or both of the carrierlayers when such layers are wetted. Typically, the applied load is agenerally tensile load resulting from the pressure exerted by theexpanding high absorbency material when the material absorbs liquid andswells. The appropriate attachment system components, such as carriersheets 98 and 100, are constructed and arranged to be sufficientlystrong to withstand this pressure and substantially avoid bursting ortearing.

In other aspects of the invention, the securing strength of theattachment system is greater than zero, and desirably is at least about0.05N/cm when the attachment system is wetted. In a particular aspect ofthe invention, the strength of the attachment system can be arranged tochange in response to the presence of the aqueous liquids. Moreparticularly, the attachment strength of the attachment system when itis contacted with an aqueous liquid can be configured to be less thanthe attachment strength of the substantially dry attachment system. Therelative decrease in attachment strength may, for example, arise from adegradation in the mechanism of interconnection between the carrierlayers. For example, where the attaching means comprises an adhesivebond, the bonding strength of the adhesive may be configured to decreaseupon a selected exposure to moisture, thereby providing a desired degreeof water-sensitivity. Alternatively, the water-sensitivity of theattaching means may arise from a degradation in the strength of thematerial forming either or both carrier layers. For example, where acarrier layer is composed of a wet-strength cellulosic tissue, thestrength of the tissue when wetted may be configured to decrease to alevel which permits an operable release from its securement to the othercarrier layer. Where a carrier layer includes meltblown fibers, themeltblown layer may be constructed to have a wet-strength whichdecreases to a level which permits an operable release from itssecurement to the other carrier layer. The decreased wet-strength of ameltblown web may, for example, be provided by tailoring the compositionof the web material and tailoring the interfiber structure of the web.Optionally, the water-sensitivity of the attaching means may arise froma combination of a degradation in the mechanism of interconnectionbetween the carrier layers and a degradation in the strength of thematerial forming either or both carrier layers.

In the various configurations of the invention, the bonded attachedzones 104 of the absorbent laminate 112 are constructed with sufficientintegrity to isolate and contain the high absorbency material withineach pocket. The securement strength between carrier layers 98 and 100is at least about 0.05N/cm, peak force, when the absorbent laminate issubstantially dry. Alternatively the dry securement strength is at leastabout 0.08N/cm, and optionally is at least about 0.1N/cm to providedesired benefits.

When absorbent laminate 112 is wet, the securement strength betweencarrier layers 98 and 100 along attached zones 104 is constructed to besufficient to maintain the general integrity of the absorbent laminate.In particular aspects of the invention, the wet securement strength isnot less than about 0.04N/cm peak force. Alternatively, the wetsecurement strength is not less than about 0.07N/cm, and optionally isnot less than about 0.09N/cm to provide desired benefits.

In desired configurations of the invention, the wet securement strengthbetween carrier layers 98 and 100 is configured so as to not excessivelylimit the swelling and expansion of the high absorbency material whenthe material is absorbing liquids, such as urine. Particular aspects ofthe invention can be configured so that the wet securement strengthbetween carrier layers 98 and 100 not more than about 5N/cm, peak force.Alternatively, the wet securement strength is not more than about 2N/cm,and optionally, is not more than about 1N/cm to provide desiredperformance.

For the purposes of the present invention, a suitable technique fordetermining the dry or wet securement strength of the attaching means isthe ASTM Standard Test Method for Peel Resistance of Adhesives ("T-PeelTest); Designation: D 1876-93, approved Jan. 15, 1993; which isdescribed in detail in the EXAMPLES section hereinbelow.

In further aspects of the invention, the saturated, expansion andswelling of the high absorbency material within the absorbent laminate112 is at least about 90% of the saturated, free-swell volume of thehigh absorbency material. Alternatively, the saturated expansion of thehigh absorbency material within the absorbent laminate is at least about95%, and optionally is at least about 97% of the saturated, free-swellvolume of the high absorbency material to provide improved performance.

A suitable technique for determining the saturated, free-swell volume ofthe high absorbency material within the absorbent laminate is theFree-Swell procedure described in detail in the EXAMPLES sectionhereinbelow.

A suitable technique for determining the saturated, expansion swellingof the high absorbency material within the absorbent laminate is theLaminate-Swell procedure described in detail in the EXAMPLES sectionhereinbelow.

In the various aspects of the invention, carrier layers 98 and 100 canbe configured with sufficient wet-strength to withstand the pressuregenerated by the expanding high-absorbency material 110 prior to thesubstantial release of the wet securement between the carrier layers. Asa result, the wet carrier layers can maintain sufficient integritysubstantially without tearing as the high-absorbency material absorbsliquid and swells. Particular aspects of the invention can includecarrier layers either or both of which are composed of a material havinga peak, wet burst strength of at least about 0.08N/cm. Alternatively,the carrier layer material can have a burst strength of at least about0.10N/cm, and optionally can have a burst strength of at least about0.12N/cm to provide improved performance.

For the purposes of the present invention, a suitable technique fordetermining the burst strength of the carrier layer material is thefollowing procedure:

WET BURST TEST PROCEDURE

Materials and Equipment

a) Compression test instrument (or tensile test instrument adapted tooperate in a compression mode) such as available from Instron or Sintechequipped with a load cell capable of measuring in the 0.01N to 5N range.The test instrument is configured to record the peak force applied tothe probe as it penetrates the carrier sheet.

b) Solid cylindrical probe, 1.27 cm diameter, at least 10 cm long. Theend which strikes the carrier sheet is convex hemispherical. The probeis mounted on the compression test instrument such that the probedescends vertically at 48 cm/min when activated.

Hollow cylindrical sample holder, 6.35 cm internal diameter,approximately 8 cm outer diameter. The sample holder is to be smooth androunded on the inside, upper end so as not to prematurely tear thesample.

d) Ring clamp to hold the sample to the top of the sample holder. Onesuitable method of holding the ring clamp securely to the sample holderis to use magnets.

e) Test solution, either distilled water or 0.85% saline (blood banksaline, nominally 8.5 gm of sodium chloride per liter of water, such asavailable from Baxter Healthcare Corporation, McGaw Park, Illinois orfrom Stephens Scientific Division of Cornwell Corporation, Riverdale,New Jersey), as appropriate.

Procedure

a) Samples are cut into 12.7×12.7 cm squares. Materials are conditionedfor at least 48 hours, and testing is conducted at ambient conditions of23±1° C. and a relative humidity of 50±2%.

b) Center the sample over the sample holder, and clamp it into place.

c) Center the sample holder under the probe.

d) Add approximately 0.25 ml of test solution.

e) Wait 30 seconds, then actuate the probe so that the probe penetratesthe sample.

Calculation

Peak force is read from the instrument display or recorder. Units areconverted to Newtons, if necessary. To present as N/cm, divide the peakforce by the circumference of the probe (3.99 cm).

The wet burst strength of several potential carrier sheets wasdetermined using the procedure described above. Each mean and standarddeviation in the following table is based on 20 samples.

For the Peak Load per unit length (N/cm): the diameter of the circularprobe used in this procedure was 1.27 cm; and these data represent theload divided by the probe circumference.

    ______________________________________                                                         Peak Load   Burst                                                             Burst       Strength                                                  Test    (Newtons)   (N/cm)                                           Material   Solution  mean    std   mean  std                                  ______________________________________                                        Barrier Tissue                                                                           water     0.67    0.11  0.168 0.028                                Forming Tissue                                                                           water     0.82    0.11  0.206 0.028                                Kleenex ® Facial                                                                     water     0.30    0.04  0.075 0.010                                Tissue                                                                        Puffs ® Facial                                                                       water     0.24    0.05  0.060 0.013                                Tissue                                                                        Hi-Dri ® Towel                                                                       water     0.86    0.09  0.216 0.023                                Bounty ® Towel                                                                       water     1.46    0.15  0.366 0.038                                Barrier Tissue                                                                           saline    0.54    0.07  0.135 0.018                                Forming Tissue                                                                           saline    0.64    0.08  0.160 0.020                                Barrier Tissue                                                                           water     0.49    0.12  0.123 0.030                                ______________________________________                                         "std" = standard deviation                                                    "barrier tissue" = 21 gsm cellulose tissue                                    "forming tissue" = 17 gsm cellulose tissue                               

These materials are known to show batch-to-batch variability as well asvariability within a batch, hence the data above suggest ranges of burststrength for some potential carrier materials. Some potential carriermaterials, such as some spunbonded nonwovens, for example, may farexceed the strengths of the tissues and paper towels reported above.

In the various configurations of the invention, the water-sensitiveattaching means and the strengths of the carrier layers 98 and 100 canbe selectively configured to permit the expansion of the wetted highabsorbency material in an arrangement that substantially avoids abursting of at least one of the carrier layers. A bursting of a carrierlayer is a visible tear which occurs in a carrier layer and is at least3 mm in length. Particular aspects of the invention can beadvantageously configured to provide an absorbent laminate 112 whereinnot more than about 25% of the pocket regions, which containhigh-absorbency material, burst when exposed to an excess of salinesolution. To provide improved performance, the absorbent laminate canalternatively have a configuration wherein not more than about 15% ofsuch pocket regions burst, and can optionally have a configurationwherein not more than about 10% of such pockets burst when exposed tothe excess of saline solution.

A suitable technique for determining the propensity of the absorbentlaminate 112 to burst is to place the absorbent composite in atransparent tray containing an amount of 0.85% saline which exceeds theamount needed to saturate absorbent laminate. After the laminate hasremained in the tray of saline for 15 minutes, the top and bottomcarrier layers of the laminate are inspected for the presence of visibletears which are at least 3 mm in length. The number of pockets with anysuch tears divided by number pockets containing high absorbency material(times 100) yields the percentage of burst pockets.

Where the water-sensitive attaching means comprises an adhesive systemwhich exhibits decreased attachment strength when wet, the selective,wet-releasability of adhesive 102 can advantageously allow the size ofpockets 108 to expand as the high absorbency material swells. As aresult, the high absorbency material is better contained in position andreduces the likelihood of rupturing carrier layers 98 and 100 when thehigh absorbency material swells.

Adhesive 102 can be applied onto either or both of carrier sheets 98 and100. In the illustrated embodiment, for example, adhesive 102 is appliedonto only one of carrier sheets 98 and 100, such as carrier sheet 100.In such structures, only one side of the quantity of high absorbencymaterial contained in each pocket 108 will be in contact with a carrierlayer having adhesive applied thereon.

In one aspect of the invention, adhesive 102 is applied in a selectedpattern, such as a sprayed pattern of discrete globules, a swirledpattern of adhesive filaments, a regular or irregular network ofadhesive filaments, a pattern of printed adhesive, a generally randomapplication of printed adhesive, or the like. Adhesive 102 can beprovided at an add-on amount of adhesive solids which is at least about1 gram per square meter of adhered area. Alternatively, the adhesive isprovided at an add-on amount of at least about 7.5 grams per squaremeter, and optionally is provided at an add-on amount of at least about10 grams per square meter. In other aspects of the invention, theadhesive add-on amount is not more than about 150 grams per square meterof adhered area. Alternatively, the adhesive add-on amount is not morethan about 65 grams per square meter, and optionally is not more thanabout 40 grams per square meter.

In the various embodiments of the invention, adhesive 102 can beprovided in an arrangement which retains high absorbency material 110within a selectively configured distribution which substantially fillsthe volume of each pocket 108. Such a configuration can better maintainthe placement and distribution of high absorbency material within eachpocket. By avoiding excessive unfilled free volume within each pocket108, the high absorbency material can be substantially prevented fromexcessively bunching up or accumulating in an isolated section of eachpocket. As a result, the absorbent capacity of the high absorbentmaterial can be more efficiently utilized.

The substantial filling of pocket regions 108 can be determined withrespect to an article laid out with the plane of the absorbent laminatein a substantially horizontal position. In this position, the projectedarea of the individual pockets 108 is substantially completely coveredby the projected area of the high absorbency material contained in eachpocket. In particular configurations, the projected area of the highabsorbency material (projected substantially perpendicular to thegeneral plane of the absorbent laminate) covers at least about 60% ofthe projected area of each pocket. Alternatively, the projected area ofthe high absorbency material covers at least about 75% of the projectedarea of each pocket, and optionally the projected area of the highabsorbency material covers at least about 95% of the projected area ofeach pocket to provide desired performance. In other configurations, theprojected area of the high absorbency material covers about 100% of theprojected area of each pocket to provide desired benefits.

Within the individual pocket regions, the particles of high-absorbencymaterial readily contact one another and are not kept substantiallyseparated apart by some other material. As a result, the absorbentlaminate 112 can have enhanced thinness and can avoid the excessivebulkiness caused by the presence of other materials. At least about 90wt % of the material contained within the pocket regions is composed ofthe high-absorbency material. Alternatively, at least about 95 wt %, andoptionally, at least about 97 wt % of the contained material is composedof the high-absorbency material.

In a particular aspect of the invention, attached zones 104 areconfigured as a regular or irregular series of non-intersecting ringspositioned around each of pocket regions 108. The attached zone ringsmay be regular or irregular in configuration and may be circular ornoncircular in shape, as desired.

Within attached zones 104 of the absorbent laminate, the attaching meansholds together the carrier layers 98 and 100 to operably define channelregions 86 located and extending between immediately adjacent individualpockets. The channels can help to more effectively and more rapidlydistribute liquids to the high absorbency material held in each of thepocket regions. The water-sensitivity of the attaching means is selectedto operably regulate and control the release of the attachment andthereby more efficiently maintain the presence and operability of thechannel regions during the absorption process. As a result, when someregions of absorbent laminate are relatively more wetted than otherregions, the operability of channels 86 can continue to providesubstantially unrestricted flow paths through the more wetted regions tothe less wetted regions of the absorbent laminate.

The non-wetted areas of the absorbent laminate can maintain thecontrolled positioning of the high-absorbency material while the wettedareas of the laminate can release in localized regions to permit anexpansion of the high-absorbency material. The expansion of the wettedhigh-absorbency material does not interfere with the selectedpositioning and distribution of the high-absorbency material in thenon-wetted areas of the laminate.

For example, in typical absorbent articles, liquids primarily enterabsorbent laminate 112 at the target section of the absorbent structure,and the pocket regions in the target section can become wetted and evensaturated prior to wetting and saturating the pocket regions in sectionsof the absorbent structure that are relatively more remote from thetarget section. With the distinctive, controlled preservation ofchannels 86, however, liquids can readily flow around and past the morewetted and swollen pockets of high absorbency material to reach the moreremote, less wetted pockets of high absorbency material. As a result,the complete absorbent capacity of substantially the entire absorbentstructure, particularly the entirety of absorbent laminate 112, can bemore efficiently utilized. The invention can advantageously provide astructure wherein the swelling of the pocket regions in the targetsection of the article does not excessively inhibit the flow of liquidto the pocket regions outside of the target section.

In one aspect of the invention, liquid permeable carrier layer 98 isconfigured to efficiently wick aqueous liquids. For example, to providedesired levels of wickability, carrier layer 98 is capable oftransporting at least 0.3 grams of saline per minute per gram of carrierlayer material measured at a wicking height of 10 centimeters.Alternatively, carrier layer 98 exhibits a liquid transporting value ofat least about 0.6 grams of saline per minute per gram of carrier layermaterial, and optionally exhibits a liquid transporting value of atleast about 2 grams of saline per minute per gram of carrier layermaterial.

In another aspect of the invention, carrier layer 98 can include apattern of embossments formed thereon with the embossed areas having arelatively higher density than the unembossed areas thereof. In theshown embodiments of the invention, the forming of the embossments orthe presence of the embossments does not provide securement betweencarrier layers 98 and 100 along attached zones 104.

At least 80 percent of the high absorbency material contained withinabsorbent laminate 112 is held within pocket regions 108. In particulararrangements, at least about 90 percent of the high absorbency materialwithin the absorbent laminate structure is contained within the pocketregions. Alternatively, at least about 95 percent of the high absorbencymaterial within the absorbent laminate is contained within the pocketregions, and optionally, about 100 percent of the high absorbencymaterial is held within the pocket regions to provide desired levels ofperformance. Accordingly, not more than about 20 percent of the highabsorbency material is held within attached zones 104 of the absorbentlaminate. Alternatively, not more than about 10 percent of the highabsorbency material is held within attached zones 104, and optionally,not more than about 5 percent of the high absorbency material iscontained within the attached zones to provide desired benefits.

The total amount of high absorbency material contained within absorbentlaminate 112 may be non-uniformly or substantially uniformly distributedamong the plurality of pockets 108. Substantially equal amounts of highabsorbency material may be contained within each individual pocket 108.Alternatively, different amounts of high absorbency material may becontained in selected pocket regions. Particular aspects of theinvention are configured with none of the individual pockets containingmore than 200 percent of the mean mass of high absorbency materialcontained in each of the pocket regions. In particular arrangements ofthe invention, the mean mass of high absorbency material in each pocketregion is at least about 0.05 gram. Alternatively, the mean mass of highabsorbency material in each pocket region is at least about 0.1 grams,and optionally is at least about 0.15 grams to provide desiredperformance. In further aspects of the invention, the mean mass of highabsorbency material in each pocket region is not more than about 2.0grams. Alternatively, the mean mass of high absorbency material is notmore than about 0.85 grams, and optionally is not more than about 0.30grams to provide desired benefits. In the various embodiments of theinvention, each pocket region can be approximately 100% filled with highabsorbency material.

In unattached zones 106, there is substantially no direct bonding orinterconnection between carrier layers 98 and 100. As a result, theunattached zones can provide individual pocket regions 108 of selectedsize. For example, each of the pocket regions can be configured toextend substantially continuously over an area of not less than about0.25 cm². Alternatively, the pocket region size is not less than about0.75 cm², and optionally, is not less than about 1.25 cm² to providepocket regions 108 having desired characteristics. In further aspects ofthe invention, the individual pocket region size is not more than about310 cm². Alternatively, the pocket region size is not more than about 70cm², and optionally, extends over an area of not more than about 5 cm²to provide desired performance.

In addition, the overall system of pockets 108 can be positioned andarranged in desired patterns to provide a selected, operable pocketarray 144 composed of the cooperating individual pockets. The pocketarray, in one aspect of the invention, can provide a pattern size havingan encompassed area extent of not less than about 5 cm². Alternatively,the pattern size is not less than about 20 cm², and optionally is notless than about 145 cm² to provide a pocket array having desiredcharacteristics. In another aspect of the invention, the pocket arraycan provide a pattern size which, for adult care type garments is notmore than about 4000 cm², and alternatively is not more than about 1000cm². For an infant care article, the pattern size is not more than about470 cm². Alternatively, the pocket region size is not more than about390 cm², and optionally extends over an area of not more than about 310cm² to provide desired performance.

In particular aspects of the invention, there is a discrete separationdistance 114 between individual pockets 108, as representatively shownin FIGS. 6 and 7. Pocket spacing distance 114 is at least about 0.15 cm.Alternatively, the pocket spacing distance is at least about 0.25centimeters, and optionally is at least about 0.3 centimeters to providedesired performance. In other aspects of the invention, pocket spacingdistance 114 is not more than about 3 centimeters. Alternatively, thepocket spacing distance is not more than about 1.9 centimeters, andoptionally is not more than about 1.2 centimeters, to provide desiredperformance. If the separation distance between individual pockets istoo small, aqueous liquids may not be able to move along and across thesurfaces of absorbent laminate 112 at a sufficiently rapid rate.

The absorbent laminate has a front waistband section 212, which isappointed for general positioning toward the front waistband section ofthe intended article, and a rear waistband section 214, which isappointed for general positioning toward the rear waistband section ofthe intended article. A crotch section 216 of the absorbent laminate isappointed for positioning at or about the intended crotch section of thearticle.

With reference to FIG. 12, absorbent laminate 112 can include secondaryattaching means 122 for securing together carrier layers 98 and 100along selected secondary attachment regions 123 to provide asubstantially water-insensitive attachment therebetween. Such secondaryattachment means can, for example, be provided by adhesive surfacebonds, adhesive encapsulation, mechanical fasteners, thermal bonds,sonic bonds, encapsulation mechanisms or the like. In an example of anencapsulation mechanism, one carrier layer can be overwrapped andappropriately fastened around the second carrier layer. The secondaryattachment regions are substantially restricted to locations spaced frompocket regions 108 by a discrete distance.

In one aspect of the invention, secondary attaching means 122 issubstantially restricted to an outer periphery 126 of absorbent laminate112. The secondary attachments may be configured to extend along boththe longitudinally extending side peripheries and laterally extendingend peripheries of the laminate, as representatively shown in FIG. 12.The secondary attachments may also be arranged to extend along only thelongitudinally extending side peripheries of the laminate, asillustrated in FIG. 13.

In another aspect of the invention, secondary attachments 122 can alsobe positioned at interstitial locations 128 between immediately adjacentpocket regions 108. Additionally, as representatively shown in FIG. 13,the secondary attachments can extend along selected peripheral regionsand selected interstitial regions.

Secondary attachments 122 can be distinctively constructed and arrangedto selectively block the releasing operation provided by water-sensitiveattachments 102. The expansion and lateral growth of each individualabsorbent pocket region 108 or selected groups of pockets can thereby belimited to a selected zone 125, as representatively shown in FIG. 14. Asa result, the lateral expansion of one pocket is substantially preventedfrom interfering with the expansion of an adjacent pocket, the overallabsorbent efficiency of the absorbent laminate can be enhanced. At theouter periphery 126 of absorbent laminate 112, secondary attachments 122can advantageously block the undesired escape of swollen, absorbent gelmaterial from the laminate structure. At interstitial locations 128,secondary attachments 122 can maintain channels 86 and thereby enhanceliquid flow to less wetted regions of the laminate 112.

For the purposes of the present invention, the term water-insensitiveattaching means (or water-insensitive attachment) refers to an attachingmeans which, when wet, has a relatively stronger securing strength thanthe respective wet strength of the water-sensitive attaching means. Therelatively stronger securement strength can, for example, be providedfor by a different, relatively stronger attaching mechanism, arelatively stronger adhesive, an adhesive provided at a relativelygreater amount of add-on, an attachment provided by a relativelystronger bonding pattern, or the like.

Secondary attachments 122 can be arranged in selected configurations,such as lines, beads, swirls, spots or the like. The illustratedembodiments, for example, can include secondary attachments whichcomprise lines of substantially water-insensitive attachment, and inparticular aspects of the invention, the attachment lines can beconfigured with a width dimension 130 of not more than about 3 cm.Alternatively, the attachment width dimension is not more than about 1cm, and optionally, is not more than about 0.3 cm to provide desiredattributes.

In addition, the secondary attachments at interstitial locations 128 canadvantageously be spaced from each of the immediately adjacent pocketsby a distance of not less than about 0.1 cm. Alternatively, the spacingis not less than about 0.5 cm, and optionally is not less than about 1cm to provide desired performance. Further aspects of the invention canbe configured with the secondary attachments at interstitial locations128 selectively spaced from each of the immediately adjacent pockets bya distance of not more than about 5 cm. Alternatively, the spacing isnot more than about 3 cm, and optionally is not more than about 2 cm toprovide desired benefits.

In particular aspects of the invention, the wet strength of thesecondary attachments can advantageously be at least about 0.09N/cm.Alternatively, the wet strength of the secondary attachments can be atleast about 0.15N/cm, and optionally can be at least about 1N/cm toprovide improved performance. In other aspects of the invention, the wetstrength of the secondary attachments is at least about 5 N/cm, andalternatively is at least about 10N/cm to provide desiredcharacteristics.

In the various configurations of the invention, the secondary attachmentmeans can be constructed to provide a Peripheral (Perimeter) Releasevalue which is not more than 15%. Alternatively, the Peripheral Releasevalue is not more than about 10%, and optionally, is not more than about5% to provide desired characteristics. Particular arrangements of thesecondary attachment means can be constructed to provide a PeripheralRelease value which is not more than about 1%, and optionally is notmore than about 0.5% to provide improved performance. A suitabletechnique for determining the Peripheral Release value is GelContainment Testing Method which is set forth in detail in the EXAMPLESsection hereinbelow.

In an example of the invention, secondary attachments 122 can beprovided by lines of substantially water-insoluble adhesive. Suitableadhesives include 34-5541, a synthetic rubber-based hot melt adhesivewhich is available from National Starch and Chemical Company, a businesshaving offices in Bridgewater, New Jersey. The attachment lines have awidth of about 0.2 cm, and can include lines which are positionedbetween adjacent pocket regions 108 and spaced from each of the adjacentpockets by a distance of at least about 0.1 cm.

Absorbent laminate 112 has a bodyside surface 116 and an outer sidesurface 118, and particular aspects of the invention can include adistribution layer 120 positioned adjacent the outer side surface ofabsorbent laminate 112. Alternatively, the distribution layer can belocated adjacent the bodyside surface of the absorbent laminate.Optionally, a pair of distribution layers 120 and 184 (FIG. 8) can bepositioned to sandwich absorbent laminate 112 therebetween, with adistribution layer on both the outer side and bodyside of the absorbentlaminate. In further arrangements of the invention, any or all of thedistribution layers 120 can be configured to provide a secondaryabsorbent body which supplements the ability of diaper 10 to containabsorbed liquids.

Distribution layer 120 can comprise a substantially unbonded mass ofhydrophilic material, such as cellulosic fibers. The cellulosic fibersmay, for example, be composed of wood pulp fluff, creped wadding, papertoweling, or the like. Distribution layer 120 can alternatively beprovided by nonwoven webs comprising hydrophilic fibers, such ashydrophilic fibers composed of polyester, polypropylene, polyethylene,cotton, and the like.

In other arrangements of the invention, distribution layer 120 cancomprise one or more layers of nonwoven fabric material comprisingnonwoven bonded webs. The fibers may be composed of polyester,polypropylene, polyethylene, cotton, and the like. The webs may bebonded by various mechanisms, such as spunbonding, thermal bonding,through-air bonding, ultrasonic bonding, infrared bonding, adhesivebonding, and the like.

Distribution layer 120 can extend over an area which is not less thanabout 50 percent of the area covered by absorbent laminate 112.Alternatively, the distribution layer area is not less than about 70percent, and optionally, is not less than about 90 percent of theabsorbent laminate area to provide desired performance. In otherarrangements of the invention, the area extent of distribution layer 120is not more than about 300 percent of the projected surface area ofabsorbent laminate 112. Alternatively, the distribution layer area isnot more than about 200 percent, and optionally, is not more than about150 percent of the absorbent laminate area.

In the various configurations of distribution layer 120, thedistribution layer, with respect to its total weight, may contain about0-20 weight percent of high absorbency material. Alternatively, theamount of high absorbency material within distribution layer 120 is notmore than about 10 weight percent, and optionally, is not more thanabout 5 weight percent to provide desired benefits.

In the illustrated embodiment, for example, distribution layer 120 cancomprise a matrix of hydrophilic fibers, such as a web of cellulosicfluff, mixed with particles of high-absorbency material. In particulararrangements, distribution layer 120 may comprise a mixture ofsuperabsorbent hydrogel-forming particles and synthetic polymermeltblown fibers, or a mixture of superabsorbent particles with afibrous coform material comprising a blend of natural fibers and/orsynthetic polymer fibers. The superabsorbent particles may besubstantially homogeneously mixed with the hydrophilic fibers, or may benonuniformly mixed. For example, the concentrations of superabsorbentparticles may be arranged in a non-step-wise gradient through asubstantial portion of the thickness (z-direction) of the distributionlayer, with lower concentrations toward the bodyside of the distributionlayer and relatively higher concentrations toward the outer side of thedistribution layer. Suitable z-gradient configurations are described inU.S. Pat. No. 4,699,823 issued Oct. 13, 1987 to Kellenberger et al., thedisclosure of which is incorporated herein by reference to the extentthat it is consistent with the present description. The superabsorbentparticles may also be arranged in a generally discrete layer within thematrix of hydrophilic fibers. In addition, two or more different typesof superabsorbent may be selectively positioned at different locationswithin or along the fiber matrix.

In particular arrangements of the invention, distribution layer 120 hasa length and/or width which can be less or greater than a correspondinglength and/or width of absorbent laminate 112. An arrangement whereinthe length and/or width of the distribution layer is greater than thelength and/or width of the absorbent laminate can provide a marginalboundary area of distribution layer 120 for capturing liquids which movepast and beyond the terminal edges of absorbent laminate 112. In theillustrated embodiment, for example, distribution layer 120 has a lengthand/or width which is within the range of approximately 75-175 % of acorresponding length and/or width of absorbent laminate 112.

The high-absorbency material employed with the various aspects of theinvention may comprise absorbent gelling materials, such assuperabsorbents. Absorbent gelling materials can be natural, syntheticand modified natural polymers and materials. In addition, the absorbentgelling materials can be inorganic materials, such as silica gels, ororganic compounds such as cross-linked polymers. The term "cross-linked"refers to any means for effectively rendering normally water-solublematerials substantially water insoluble but swellable. Such means caninclude, for example, physical entanglement, crystalline domains,covalent bonds, ionic complexes and associations, hydrophilicassociations, such as hydrogen bonding, and hydrophobic associations orVan der Waals forces.

Examples of synthetic absorbent gelling material polymers include thealkali metal and ammonium salts of poly(acrylic acid) and poly(methacrylic acid), poly(acrylamides), poly(vinyl ethers), maleicanhydride copolymers with vinyl ethers and alpha-olefins, poly(vinylpyrrolidone), poly(vinylmorpholinone), poly(vinyl alcohol ), andmixtures and copolymers thereof. Further polymers suitable for use inthe absorbent structure include natural and modified natural polymers,such as hydrolyzed acrylonitrile-grafted starch, acrylic acid graftedstarch, methyl cellulose, carboxymethyl cellulose, hydroxypropylcellulose, and the natural gums, such as alginates, xanthan gum, locustbean gum and the like. Mixtures of natural and wholly or partiallysynthetic absorbent polymers can also be useful in the presentinvention. Other suitable absorbent gelling materials are disclosed byAssarson et al. in U.S. Pat. No. 3,902,236 issued Aug. 26, 1975.Processes for preparing synthetic absorbent gelling polymers aredisclosed in U.S. Pat. No. 4,076,663 issued Feb. 28, 1978 to Masuda etal. and U.S. Pat. No. 4,286,082 issued Aug. 25, 1981 to Tsubakimoto etal.

Synthetic absorbent gelling materials typically are xerogels which formhydrogels when wetted. The term "hydrogel", however, has commonly beenused to also refer to both the wetted and unwetted forms of thematerial.

As mentioned previously, the high-absorbency material used in retentionportion 48 is generally in the form of discrete particles. The particlescan be of any desired shape, for example, spiral or semi-spiral, cubic,rod-like, polyhedral, etc. Shapes having a large greatestdimension/smallest dimension ratio, like needles, flakes, and fibers,are also contemplated for use herein. Conglomerates of particles ofabsorbent gelling material may also be used in retention portion 48.

Preferred for use are particles having an average size of from about 20micrometers to about 1 millimeter. "Particle size" as used herein meansthe weighted average of the smallest dimension of the individualparticles.

In the various aspects of the invention, particular components ofabsorbent structure 32, such as absorbent laminate 112 and distributionlayer 120, can include a quantity of high-absorbency materialdistributed therein. Selected superabsorbent polymers having improvedabsorbent properties can be important for maximizing the performancewhile retaining the desired thinness of the absorbent article.

In another aspect of the invention, the high absorbency materialemployed with absorbent laminate 112 exhibits an Absorbency Under Load(AUL) value of at least about 10 grams of liquid saline per gram of highabsorbency material, as determined under a pressure of 0.9 psi (6.2kPa). Alternatively, the high absorbency material exhibits an AUL valueof at least about 15 grams per gram, and optionally, exhibits an AULvalue of at least about 20 grams per gram to provide desiredperformance. As used herein, the Absorbency Under Load value of aparticular superabsorbent material refers to the amount, in grams, of anaqueous solution of sodium chloride (0.9 weight percent sodium chloride)which 1 gram of superabsorbent material can absorb in 60 minutes whileunder a selected restraining load.

A particular example of a high absorbency material suitable for use inthe present invention is FAVOR SAB 870 superabsorbent polymer producedby Stockhausen, Inc., a business having offices in Greensboro, NorthCarolina.

It has been discovered that the performance of a superabsorbent materialrelates to the ability of the superabsorbent material to absorb a liquidnot only while under a single given restraining force, such as about 0.3pound per square inch (about 2 kPa), but also over a broader range ofrestraining forces, such as about 0.01-0.9 pound per square inch (about0.7-6.2 kPa). The ability of a superabsorbent material to absorb aliquid under a variety of different restraining pressures has, for thepurposes of this application, been quantified as the Pressure AbsorbencyIndex.

The Pressure Absorbency Index is the sum of the Absorbency Under Loadvalues for a superabsorbent material determined under the followingloads: 0.01 pound per square inch (0.07 kPa); 0.29 pounds per squareinch (2.0 kPa); 0.57 pounds per square inch (3.9 kPa); and 0.90 poundsper square inch (6.2 kPa). That is, the Absorbency Under Load values fora given superabsorbent material are determined under the restrainingforces set forth above according to the method set forth in the documentidentified below. The Absorbency Under Load values determined under therestraining loads set forth above are then totaled to determine thePressure Absorbency Index.

Superabsorbent materials useful in the present invention have a PressureAbsorbency Index of at least about 100, particularly of at least about105, more particularly of at least about 110, even more particularly ofat least about 120; and most particularly of at least about 140.

Superabsorbent materials useful in the present invention may alsosuitably have a 16-hour extractables level, determined as set forth inthe document identified below, of less than about 13 weight percent,particularly of less than about 10 weight percent, more particularly ofless than about 7 weight percent, and even more particularly of lessthan about 3 weight percent.

Suitable techniques for determining the AUL value, Pressure AbsorbencyIndex and extractables level of high absorbency material 110 are setforth in copending U.S. patent application Ser. No. 016,312; entitled"ABSORBENT COMPOSITE"; of M. Melius et al.; filed on Feb. 24, 1993(Attorney Docket No. 10,838); and in its associated continuation-in-partapplication filed on even date herewith; the disclosures of which arehereby incorporated by reference to the extent that they are consistentherewith.

Where distribution layer 120 comprises particles of superabsorbentpolymer distributed within a matrix of hydrophilic fibers, such as alayer of wood pulp fluff, the hydrophilic fibers and high-absorbencyparticles can be provided in a fiber-to-particle ratio which is not lessthan about 50:50, and desirably, is not less than about 80:20. Thisratio is alternatively not less than about 90:10, and optionally, is notless than about 95:5, by weight, to provided desired performance. Suchfiber-to-particle ratios can be particularly desireable in the targetzone of the absorbent structure. In particular embodiments of theinvention, the fiber-to-particle weight ratio is within the range ofabout 95:5 to 100:0 to provide desired performance.

For example, the invention can be configured to provide a medium-sizearticle which has been referred to as a "Step 3" size diaper. Sucharticles can comprise a distribution layer 120 in the form of a fluffpad which includes 4-25 grams of wood pulp fluff. The pad canalternatively include about 5-20 grams of fluff, and can optionallyinclude about 6-15 grams of fluff to provide desired benefits. Thewoodpulp fluff generally provides shape and form to diaper 10, andcarries and positions the particles of superabsorbent polymer or otherhigh-absorbency material. Distribution layer 120 can also contain about0-12 grams of superabsorbent polymer, and in the shown embodiment, thedistribution layer is substantially free of superabsorbent polymer.

The hydrophilic fibers and high-absorbency particles can be configuredto form an average composite basis weight which is within the range ofabout 90-650 gsm. Again, such basis weight is particularly desireable inthe target zone of the absorbent structure. In certain aspects of theinvention, the average composite basis weight is within the range ofabout 110-550 gsm, and optionally is within the range of about 130-450gsm to provide desired performance.

To provide the desired thinness dimension to the absorbent article,retention portion 48 is configured with a thickness which is not morethan about 0.6 cm. Alternatively, the thickness is not more than about0.53 cm, and optionally is not more than about 0.5 cm to provideimproved benefits. For the purposes of the present invention, thethickness is determined under a restraining pressure of 0.2 psi (1.38kPa).

The density of distribution layer 120 or other component of theabsorbent article can be calculated from its basis weight and thickness.With respect to diapers, for example, the weight and thickness aremeasured with respect to samples taken from newly unpacked, unfolded anddry diapers at a restraining pressure of 0.2 psi (1.38 kPa). Formeasuring thickness, a suitable device is a TMI foam thickness gauge,Model No. TM1-49-21 or its equivalent. The apparatus is available fromTesting Machines, Inc. of Amityville, New York.

The fluff and superabsorbent particles can be selectively placed intodesired zones of distribution layer 120. For example, the fluff basisweight may vary across the width dimension of distribution layer 120.Alternatively, relatively larger amounts of fluff may be positionedtoward the front waistband end of the distribution layer. For example,see U.S. Pat. No. 4,585,448 issued Apr. 29, 1986, to K. Enloe.

In the illustrated embodiment, the majority of the superabsorbentmaterial can be distributed down a medial region of distribution layer120 which extends along the length dimension of the retention portionand measures about 1-10 inches (about 2.54-25.4 cm) in width. The medialregion may optionally have a width within the range of about 1.5-4inches (about 3.8-10.2 cm). In addition, the superabsorbent material mayhave a selected zoned placement to reduce the amount of superabsorbentmaterial located proximate the side and end edges of the distributionlayer. The reduced amounts of superabsorbent material at the edges ofthe distribution layer can help improve the containment of thesuperabsorbent particles within the fibrous fluff matrix of distributionlayer 120. The pulsed, zoned placement of the superabsorbent materialcan, for example, be achieved by the method and apparatus described incopending U.S. patent application Ser. No. 07/462,363 of C. Pieper etal. filed Jan. 9, 1990, and entitled "Method and Apparatus forIntermittently Depositing Particulate Material in a Substrate" (AttorneyDocket No. 8761), the disclosure of which is hereby incorporated byreference to the extent that it is consistent herewith.

In a particular aspect of the invention, absorbent structure 32 isgenerally T-shaped with the laterally extending cross-bar of the "T"generally corresponding to the front waistband portion of the absorbentarticle for improved performance, especially for male infants. In theillustrated embodiments, the retention portion across the ear section ofthe front waistband region of the article has a cross-directional widthof about 9 inches (about 23 cm), the narrowest portion of the crotchsection has a width of about 3.5 inches (about 8.9 cm) and the backwaistband region has a width of about 4.5 inches (about 11.4 cm).

With reference to FIGS. 2 and 4, the entire absorbent structure 32, orany individual portion thereof, such as distribution layer 120, can beoverwrapped in a hydrophilic high wet-strength envelope web, such as ahigh wet-strength tissue or a synthetic fibrous web. Such overwrappingweb can also increase the in-use integrity of the absorbent structure.The web can be suitably bonded, such as with adhesive, to othercomponents of the product construction.

Absorbent wrap 70 typically comprises a single layer of wrapsheetmaterial. Optionally, the wrap may comprise a multi-element wrapsheetwhich includes a separate bodyside wrap layer 71 and a separate outerside wrap layer 73, each of which extends past all or some of theperipheral edges of retention portion 48. Such a configuration of thewrap sheet can, for example, facilitate the formation of a substantiallycomplete sealing and closure around the peripheral edges of retentionportion 48. In the back waistband portion of the illustrated diaper, theabsorbent wrap may also be configured to extend an increased distanceaway from the periphery of the retention portion to add opacity andstrength to the back ear sections of the diaper. In the illustratedembodiment, the bodyside and outer side layers of absorbent wrap 70extend at least about 0.5 inch (about 1.27 cm) beyond the peripheraledges of the retention portion to provide an outwardly protruding,flange-type bonding area over which the periphery of the bodysideportion of the absorbent wrap may be completely or partially connectedto the periphery of the outer side portion of the absorbent wrap.

The bodyside and outer side layers of a multi-element wrap sheet 70 maybe composed of substantially the same material, or may be composed ofdifferent materials. For example, the outer side layer of the wrap sheetmay be composed of a relatively lower basis weight material having arelatively high porosity, such as a wet strength cellulosic tissuecomposed of softwood pulp. The bodyside layer of the wrap sheet maycomprise one of the previously described wrap sheet materials which hasa relatively low porosity.

To provide the bonding between the bodyside and outer side portions ofabsorbent wrap 70, an adhesive, such as National Starch 33-9156 adhesive(a polyvinylacetate-based emulsion), can be printed onto the appointedbonding areas 74 of the absorbent wrap with, for example, arotogravure-type system. Rotogravure-type adhesive applicators areavailable from Egan Machinery Division, a business having offices atOconto Falls, Wisconsin. Retention portion 48 can then be placed betweenthe bodyside and outer side portions of absorbent wrap 70 and the matingedges of the absorbent wrap portions can be bonded together to provide agenerally complete peripheral seal along substantially the entireperimeter of retention portion 48.

Due to the thinness of retention portion 48 and the high superabsorbentconcentrations within the retention portion, the liquid uptake rates ofthe retention portion, by itself, may be too low, or may not beadequately sustained over three insults of liquid into the absorbentstructure. The addition of a layer of surge management material into theabsorbent structure, however, can advantageously improve the overalluptake rate of the composite absorbent structure. Surge managementportion 46 is typically less hydrophilic than retention portion 48, andhas an operable level of density and basis weight to quickly collect andtemporarily hold liquid surges, and to transport the liquid from itsinitial entrance point to selected regions of absorbent structure 32,particularly retention portion 48. This configuration can help preventthe liquid from pooling and collecting on the portion of the absorbentgarment positioned against the wearer's skin, thereby reducing thefeeling of wetness by the wearer.

Various woven and nonwoven fabrics can be used to construct surgemanagement portion 46. For example, the surge management portion may bea layer composed of a meltblown or spunbonded web of polyolefin fibers.The surge management layer may also be a bonded-carded-web composed ofnatural and synthetic fibers. The surge management portion may becomposed of a substantially hydrophobic material, and the hydrophobicmaterial may optionally be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.

In addition, the surge management layer can be configured with anaverage bulk density which is not more than about 0.10 g/cc, determinedat 0.2 psi (1.38 kPa). Alternatively, the bulk density of the surgemanagement layer is within the range of about 0.02-0.06 g/cc to provideimproved effectiveness. The types of nonwoven materials that may beemployed include powder-bonded-carded webs, infrared bonded carded webs,and through-air-bonded-carded webs. The infrared and through-air bondedcarded webs can optionally include a mixture of different fibers, andthe fiber lengths within a selected fabric web may be within the rangeof about 1.0-3.0 inch (about 2.54-7.62 cm).

Surge management portion 46 can have a generally uniform thickness andcross-sectional area. Alternatively, a configuration can be employedwherein the bodyside surface area of the surge management portion isgreater or less than the surface area of a section taken along an X-Yplane located below the bodyside surface of the surge managementportion.

With reference again to FIGS. 1, 2 and 4, the absorbent articlerepresented by diaper 10 can generally comprise a liquid surgemanagement portion 46 and an absorbent retention portion 48 adjacentlyarranged in direct, contacting liquid communication with the surgemanagement portion. In the illustrated embodiment, for example, thesurge management portion is positioned on the body side of absorbentlaminate 112. Optionally, the surge management portion may be positionedon the outer side of the absorbent laminate. As representatively shownin FIGS. 2 and 4, respectively, surge management portion 46 mayalternatively be configured for placement adjacent an inwardly facing,bodyside of topsheet 28, or adjacent an outer side of the topsheet.

In the various embodiments of the invention, at least a part of surgemanagement portion 46 is located within target zone 53, and inparticular arrangements, the surge management portion has an arealextent which extends completely over target zone 53. Retention portion48 is positioned in liquid communication with surge management portion46 to receive liquids released from the surge management portion and tohold and store the liquid. In the shown embodiments, surge managementportion 46 comprises a separate layer which is positioned over another,separate layer comprising the retention portion, thereby forming adual-layer arrangement. The surge management portion serves to quicklycollect and temporarily hold discharged liquids, to transport suchliquids from the point of initial contact and spread the liquid to otherparts of the surge management portion, and then to eventually releasesuch liquids into the layer or layers comprising retention portion 48.

The layer comprising the surge management portion is substantially freeof absorbent gelling material. Surge management portion 46 may, however,contain a very small amount of gelling material to help acquire aninitial liquid surge, but the amount should not be excessive. Whenexcessive amounts of absorbent gelling material are maintained in surgemanagement portion 46, however, the gelling material can cause thestructure to retain and hold unacceptably high amounts of the liquid. Inaddition, the transport of liquids away from target zone 53 to othersections of absorbent structure 32, particularly retention portion 48,can be undesirably impaired.

As mentioned previously, surge layer 46 can be a separately formedlayer, which lies adjacent the outerwardly facing surface of topsheet 28between the retention portion and topsheet. Thus, surge managementportion 46 need not extend through the entire thickness of absorbentstructure 32. The retention portion can optionally include a recess areawhich wholly or partially surrounds surge management portion 46, or theretention portion can be entirely positioned below the surge managementportion. The arrangement which includes the recess in retention portion48 can advantageously increase the area of contact and liquidcommunication between the retention portion and surge management portion48. It should be understood, however, that surge management portion 46could optionally be constructed to extend through the entire thicknessof absorbent structure 32 so that the capillary flow of liquid intoretention portion 48 occurs primarily in the generally sideways (X-Y)direction.

A capillary force differential can be provided at the interface betweenthe retention portion 48 and the material immediately adjacent thebodyside of the retention portion to improve the containmentcharacteristics of absorbent structure 32. For example, if the surgemanagement portion 46 is a layer positioned immediately adjacent to theretention portion, and if the surge layer is appropriately configured toprovide and maintain a relatively lower capillary attraction, ascompared to the capillary attraction exhibited by retention portion 48,then liquid surges occurring in target zone 53 tend to be desorbed morereadily from the surge management portion and into the retentionportion. Because retention portion 48 can thereby have a relativelyhigher capillarity than surge management portion 46, the liquid surgestend to be drawn into retention portion 48 and distributed to the moreremote regions thereof by wicking along the plane generally defined bythe retention portion.

The surge management portion can be of any desired shape consistent withthe absorbency requirements of absorbent structure 32. Suitable shapesinclude for example, circular, rectangular, triangular, trapezoidal,oblong, dog-boned, hourglass-shaped, or oval. Preferred shapes of thesurge management portion are those that increase the contacting, liquidcommunicating surface area between surge management portion 46 andretention portion 48 so that the relative capillarity difference betweenthe portions can be fully utilized. In certain embodiments, the surgemanagement portion can be generally rectangular-shaped with a topsurface area within the range of about 15-102 in² (about 97-660 cm²). Inthe shown embodiment, surge layer 46 has a top surface area of about 68square inches (about 440 cm²).

In the various embodiments of the invention, such as the arrangement ofFIG. 4 where surge management portion 46 is interposed between topsheet28 and retention portion 48, the surge management portion can comprise anonwoven fabric which has a basis weight within the range of about17-102 gsm and includes at least about 25 wt % of bicomponent fibers toprovide a desired bicomponent fiber bond-matrix. Up to 100% of the surgefabric can be composed of bicomponent fibers, and accordingly, 0-75 wt %of the fabric may comprise non-bicomponent fibers. In addition, thefabric can comprise a blend of smaller diameter fibers and relativelylarger diameter fibers. The smaller sized fibers have a denier of notmore than about 3 d, and alternatively have a denier within the range ofabout 0.9-3 d to provide desired benefits. The larger sized fibers havea denier of not less than about 3 d, and optionally have a denier withinthe range of about 3-18 d to provide desired performance. The lengths ofthe fibers employed in the surge management materials are within therange of about 1-3 in (about 2.54-7.62 cm). The bond-matrix and theblend of fiber deniers can advantageously provide for and substantiallymaintain a desired pore size structure.

For example, the surge management portion may comprise a nonwovenfibrous web which includes about 75 percent polyester fibers of at least6 denier, such as PET (polyethylene terephthalate) fibers available fromHoechst Celanese, a business having offices at Charlotte, NorthCarolina. The polyester fibers have a length ranging from about 1.5-2.0inches (about 3.8-5.1 cm) in length. The remaining 25 percent of thefibrous web can be composed of bicomponent binder fibers which are notmore than 3 denier, and in the shown embodiment, are about 1.5 denier.The bicomponent fiber length ranges from about 1.5-2 inches (about3.8-5.1 cm). Suitable bicomponent fibers can, for example, be a wettablepolyethylene/polypropylene bicomponent fiber, available from Chisso, abusiness having offices located in Osaka, Japan. The bicomponent fibercan be a composite, sheath-core type with the polypropylene forming thecore and polyethylene forming the sheath of the composite fiber. Thepolyester fibers and bicomponent fibers are generally homogeneouslyblended together and are not in a layered configuration. The fibers canbe formed into a carded web which is thermally bonded, such as bythrough-air bonding or infrared bonding. As another example, the surgemanagement portion may be composed of a bonded carded web which has abasis weight of about 50 gsm and includes a mixture of polyester (PET)single-component fibers and PET/polyethylene bicomponent fibers. The PETfibers comprise about 60 wt % of the nonwoven fabric, and are about 6denier with an average fiber length of about 2 in (about 5.1 cm). ThePET/polyethylene bicomponent fibers comprise about 40 wt % of thefabric, and are about 1.8 denier with an average fiber length of about1.5 in (about 3.8 cm). The PET forms the core and the polyethylene formsthe sheath of the fiber. In optional constructions, the larger-sized,PET single-component fibers may be replaced by bicomponent fibers. Infurther optional arrangements, polypropylene/polyethylene bicomponentfibers may be employed to form the bicomponent fiber portion of any ofthe described fabrics. In addition, the bicomponent fibers may be flatcrimped or helically crimped.

Referring to FIG. 2, surge management portion 46 can be advantageouslyconfigured for placement against the bodyside of topsheet 28.Accordingly, an outerward major surface of the surge management portionwould be immediately adjacent and contact the topsheet, and theopposite, innerward major surface of the surge management portion wouldcontact the skin of the wearer. In the shown embodiment, backsheet 30defines a front waistband section 12, a rear waistband section 14, andan intermediate or crotch section 16 interconnecting the front and rearwaistband sections. The backsheet has predetermined width and lengthdimensions, and an absorbent body 32 is superposed on the backsheet.Topsheet layer 28 is disposed in facing relation with the absorbent bodyto generally sandwich the absorbent body between the backsheet andtopsheet layers, and the topsheet has an appointed outer side surfaceand an appointed bodyside surface. A width dimension of topsheet 28 isconfigured to extend completely over the width of the absorbent body inat least a portion of the crotch section of the absorbent body. With theshown embodiment, the topsheet is also substantially coextensive withthe backsheet width over at least a portion of the backsheet crotchsection. A surge management portion, such as surge layer 46, is locatedon the bodyside surface of the topsheet layer, with the surge layerhaving a width dimension which is less than the width of said topsheetlayer.

Where surge management portion 46 is configured for placement adjacentthe bodyside of topsheet 28, the surge management portion can be acomposite, liner-surge web 76. The composite web can include a bodysidelayer portion and an outer side layer portion. The layer portions can beseparately laid and can have different structures and compositions. Thefibers within each layer and the intermingling fibers between the layerportions are then suitably interconnected (such as by powder bonding,point bonding, adhesive bonding, latex bonding, or by through-air orinfrared thermal bonding) to form a composite web. The resultantcomposite web has a total basis weight of not more than about 102 gsm.Alternatively, the total basis weight is within the range of about 24-68gsm, and optionally is within the range of about 45-55 gsm. In addition,the total average density of the composite web is not more than about0.10 g/cc, and optionally is not more than about 0.05 g/cc, asdetermined at 0.2 psi (1.38 kPa).

The outer side, surge layer has a basis weight within the range of about17-50 gsm and includes at least about 25 wt % of bicomponent fibers toprovide a desired bicomponent fiber bond-matrix. The outer side layeralso comprises a blend of smaller diameter fibers and relatively largerdiameter fibers. The smaller sized fibers have a denier within the rangeof about 0.9-3 d, and the larger sized fibers have a denier within therange of about 3-15 d. The bond-matrix and the blend of fiber denierscan advantageously provide for and substantially maintain a desired poresize structure within the outer side layer.

For example, the outer side layer may be composed of a carded web whichhas a basis weight of about 34 gsm and includes a mixture of polyester(PET) single-component fibers, available from Hoechst-Celanese, andpolyethylene/PET (PE/PET) sheath-core bicomponent fibers, available fromBASF Corp., Fibers Division, a business having offices in Enka, NorthCarolina. The PET fibers can comprise about 60 wt % of the outer sidelayer and have a denier of about 6 with an average fiber length of about2 in (about 5.1 cm). The polyethylene/PET bicomponent fibers compriseabout 40 wt % of the outer side layer, and have a denier of about 1.8with an average fiber length of about 1.5 in (about 3.8 cm). Optionally,the larger-sized, PET single-component fibers may be replaced bybicomponent fibers. As a further option, polyethylene/polypropylene(PE/PP), sheath-core bicomponent fibers may be employed to form thebicomponent fiber portion of any of the described fabrics. SuitablePE/PP bicomponent fibers are available from Chisso Corp., a businesshaving offices in Osaka, Japan.

The bodyside, liner layer includes at least about 90 wt %, andpreferably 100 wt %, of bicomponent fibers to provide desired levels oftactile softness and abrasion resistance. The bodyside layer has a basisweight of at least about 10 gsm, and the bicomponent fiber size iswithin the range of about 0.9-3 denier with a fiber length within therange of about 1-3 in (about 2.54-7.62 cm). Alternatively, the fiberdenier is within the range of about 1.5-2.5, and optionally, is about1.8 denier. A preferred fiber length is about 1.5 in (about 3.8 cm). Forexample, bodyside layer 80 may comprise a carded web which has a basisweight of about 17 gsm and is composed of 100% PET/polyethylene,sheath-core bicomponent fibers, obtained from BASF Corp., with a fiberdenier of about 1.8 and fiber lengths of about 1.5 in (about 3.8 cm).

In a particular embodiment of the composite surge management portion,the outer side layer forms approximately 65 weight percent of thecomposite web and is composed of a blend of polyester fibers andbicomponent fibers. With respect to this blended outer side layer, about60 weight percent of the blended layer is composed of polyester fibersof at least about 6 denier and with a fiber length within the range ofabout 1.5-2 inches (about 3.8-5.1 cm). The remaining 40 percent of theblended layer is composed of bicomponent fibers of not more than about 3denier, and preferably about 1.8 denier, with fiber lengths within therange of about 1.5-2 inches (about 3.8-5.1 cm). The bodyside layer 80comprises the remaining 35 weight percent of the composite web, and iscomposed of bicomponent fibers having a denier within the range of about0.9-3 to provide a soft liner type material appointed for placementagainst a wearer's skin. In a particular embodiment, the bodyside layerof the composite web has a basis weight of about 15 gsm and is composedof bicomponent fibers of about 2 denier.

Another embodiment of the composite web can comprise a bodyside layercomposed of about 100% polyethylene/polyester sheath-core bicomponentfibers of not more than about 3 denier. The bodyside layer has a basisweight of about 15 gsm. In addition, this embodiment of the compositeweb includes an outer side layer composed of a 50/50 blend of polyesterfibers of about 6 denier and polyester/polyethylene, sheath-corebicomponent fibers of not more than about 3 denier.

In the various embodiments of the invention, the surge layer width iswithin the range of about 16-100 % of the topsheet width. The surgelayer width is alternatively at least about 24% of the topsheet width,and optionally, is at least 50% of the topsheet width to provide desiredlevels of effectiveness.

The various embodiments of surge management portion 46 may extend overthe complete length of retention portion 48, or may extend over only apart of the retention portion length. Where the surge management portionextends only partially along the length of the retention portion, thesurge management portion may be selectively positioned anywhere alongabsorbent structure 32. For example, surge management portion 46 mayfunction more efficiently when it is offset toward the front waistbandof the garment and transversely centered within front section 49 ofabsorbent structure 32. Thus, surge management portion 46 can beapproximately centered about the longitudinal center line 58 ofabsorbent structure 32, and positioned primarily in central region 54 offront section 49 of absorbent structure 32. In the illustratedembodiment, none of surge management portion 46 is located in earregions of 50 and 52.

The generally forward, offset positioning of surge management portion 46can be defined by specifying the percentage of the top surface area ofsurge management portion 46 which is found forward of a particularreference point, such as transverse centerline 24, along the length ofabsorbent structure 32. The positioning of surge management portion 46can alternatively be defined with respect to the volume or weightpercent of the surge management portion which is positioned forward of areference point.

The surge management portion and the topsheet layer each have aneffective average pore size. In constructions where the surge managementportion is located adjacent the outer side of the topsheet, theeffective average pore size of the surge management material ispreferably smaller than the effective average pore size of said topsheetmaterial, and the material of the surge management portion is preferablymore hydrophilic than the topsheet material.

With the various embodiments of the invention, the basis weight of surgemanagement portion 46 is at least about 24 grams per square meter (gsm),alternatively is at least about 40 gsm, and optionally is at least about45 gsm to help provide the total void volume capacity desired foreffective operation. In a particular aspect of the invention, the basisweight is not more than about 300 gsm, alternatively, is not more thanabout 150 gsm, and optionally, is not more than about 100 gsm to providedesired advantages. In a further aspect of the invention, the surgemanagement portion has a basis weight which is within the range of about40-60 gsm, and optionally, is within the range about 45-55 gsm toprovide improved effectiveness. In a particular embodiment, the basisweight is about 50 gsm.

The amount of basis weight can be important for providing a totalholding capacity which is adequate to temporarily retain the amount ofliquid that is typically discharged by a wearer during a singlesurge/insult of liquid into the absorbent article. For instance, a basisweight which is too low can result in excessive pooling of liquidagainst the wearer's skin or excessive run-off of liquid. It will bereadily apparent that absorbent articles requiring more surge capacitymay also require proportionally greater amounts of surge managementmaterial. The surge management material, however, need not be of uniformbasis weight throughout its areal extent, but instead can be arranged sothat some sections have more surge management material compared to othersections. For the purposes of the present invention, the effective basisweight will be the weight of the surge management material divided bythe area over which the surge management portion extends.

The following Examples are presented to provide a more detailedunderstanding of the invention. The Examples are intended to berepresentative, and are not intended to specifically limit the scope ofthe invention.

EXAMPLES Delamination Testing Procedure

The laminate composites were tested for delamination, attachmentstrength on a computerized tensile testing machine. Suitable machinesinclude, for example, a Sintech brand tensile tester which is equippedwith a 22N maximum force load cell and is accurate to ±0.005N. Thesample holders or "jaws" are configured to be at least as wide as thewidest sample being tested. Sintech is a business having offices inStoughton, Massachusetts. Equivalent testing instruments are availablefrom other manufacturers.

The procedure was based on the ASTM Standard Test Method for PeelResistance of Adhesives ("T-Peel Test); Designation: D 1876-93, approvedJan. 15, 1993. The procedure was modified as follows:

    ______________________________________                                        § 4.1.1                                                                         Some of the specimens had a maximum load less than                            15% of the upper limit of the loading range.                           §§ 4.2 & 6.1                                                               Materials were conditioned for at least 2 days under                          the conditions specified; however, they were tested at                        laboratory conditions of 22 ± 2° C. and a relative                  humidity of 50 ± 20%. Materials were tested within                         2 hours of being removed from the conditioning room.                   § 5.2                                                                           Unless otherwise specified, samples were cut into                             102 mm wide test specimens, consistent with Note 6 in                         the ASTM procedure.                                                    § 5.3                                                                           The number of samples for each code is as given in the                        data tables.                                                           § 7.1                                                                           Head speed of 300 mm/minute was used.                                  § 7.3                                                                           Testing was done to a 60 mm length. The peak force                            was recorded in Newtons. The peak force is then                               divided by the width of the test sample to provide                            force per unit width (N/cm).                                           Note 10                                                                              Peak strength, energy, and average load were all                              recorded. Note that average peel strength will have                           little meaning in cases where the sample tears rather                         than delaminates.                                                      ______________________________________                                    

Samples were tested "dry", or "wet" with distilled water, or wetted with"saline" solution (0.85 % sodium chloride in water), as indicated in thetables below. The "wet" and "saline" samples were mounted in the jaws ofthe test instrument while dry, and were then sprayed with the water orsaline (1 to 3 grams) using a hand-held spray bottle. 30 seconds afterthe last spray, the samples were tested.

EXAMPLES 1-8 Sample Preparation Procedure

Samples were prepared using assembly techniques consistent with U.S.Pat. No. 4,055,180 issued Oct. 25, 1977 to Karami (see, for example,column 3, line 26 and following). Polyethylene film (0.18 mm thick, 40gsm) and conventional cellulose tissue (17 gsm) were cut into 127 mm×305mm sections. The tissue was fused to the polyethylene film using aVertrod Corp. Thermal Impulse Heat Sealing Machinery Model 8MG-3/4 heatsealing apparatus.

As representatively shown in FIG. 9, polyethylene sheet 220 was placedover the tissue sheet 222. A silicone treated release paper 224 coveredthe polyethylene film to prevent sticking to the unheated bar 226 of theheat sealing unit. The heated bar 228 was arranged to contact t issue222.

Temperature and dwell time settings were set to achieve an operable bondand seal. Temperature and dwell time settings which were too high meltedthrough the polyethylene sheet. Settings which were too low did notstrongly bond the materials. In the examples, the temperature was set at"7", and a dwell time of approximately 2 seconds was used for bonding.

A series of eight seal lines were made across the width of thetissue/polyethylene to bond the materials together. Each of the seallines was 17 mm±4 mm wide, and the seal lines were about 16 mm apart,center to center. A longitudinal fusion line was made along one longedge of the sheets to form seven slots. Into each of these slots wasplaced 0.25±0.01 gram of FAVOR 870 polyacrylate superabsorbent. Theslots were sealed with another longitudinal line, leaving a 16 mm gapbetween the lines, thereby creating seven pockets and leaving seven newslots. The process was then repeated twice more to provide an absorbentlaminate structure having 21 pockets, with each pocket containingapproximately 0.25 grams of superabsorbent.

Prior to testing, the absorbent laminate was cut longitudinally toprovide three strips, with each strip measuring approximately 4.2 cm inwidth and including seven pockets of superabsorbent. The test data beloware based on these 4.2 cm wide laminates

Except as specified otherwise, the term "delamination" indicates thatthe carriers separated along the bonding line.

Results

    ______________________________________                                        Peel Testing of Heat Sealed Poly/Tissue Composites                                                       Force                                                                         per unit                                                            Peak Force                                                                              width                                              Sample Condition (Newtons) (N/cm) Observations                                ______________________________________                                         1     dry       1.04      0.25   Delamination, NO                                                              tearing.                                     2     dry       0.73      0.17   Delamination, NO                                                              tearing.                                     3     dry       0.69      0.16   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                        4     dry       0.27      0.06   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                        5     dry       0.24      0.06   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                        6     dry       0.39      0.09   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                        7     dry       0.55      0.13   Delamination, NO                                                              tearing.                                     8     dry       0.32      0.08   Delamination, NO                                                              tearing.                                     9     dry       0.20      0.05   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                       10     dry       0.32      0.08   Some                                                                          delamination,                                                                 also tissue did                                                               tear.                                       11     saline    0.26      0.06   Slight                                                                        delamination,                                                                 tissue DID tear.                            12     saline    0.23      0.05   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                       13     saline    0.16      0.04   Slight                                                                        delamination,                                                                 tissue DID tear.                            14     saline    0.19      0.05   Some                                                                          delamination,                                                                 also tissue DID                                                               tear.                                       15     saline    0.12      0.03   Delamination, NO                                                              tearing.                                    16     saline    0.23      0.06   Slight                                                                        delamination,                                                                 tissue DID tear.                            ______________________________________                                    

Conclusion

Samples prepared in a manner consistent with Karami (U.S. Pat. No.4,055,180), resulted in composites which had either insufficient wetstrength or had carrier sheets which tore when wet. Samples 1-10 showsufficient dry strength, but samples 11-14 and 16 tore rather thandelaminated when wet. Sample 15 had insufficient wet strength.

EXAMPLES 17-22 Sample Preparation Procedure

A metal die was prepared to simulate one section of the embossing rolldescribed in U.S. Pat. No. 4,414,255 issued Nov. 8, 1993 to Tokuyama(see, for example, column 5, lines 3-17). As representatively shown inFIG. 10, 55 mm×118 mm aluminum plate was constructed with a multiplicityof holes 230 and pins 232. Fourteen, 2.6 mm diameter holes were drilledinto the plate. The holes 230 were aligned, and were spaced with a 5.2mm, edge-to-edge distance between each hole. Eight 0.5 mm diameter steelpins 232 were mounted around each of the holes, with four pins locatedat each of two opposed sides of each hole. Accordingly, eight pins werelocated between adjacent holes. The pins were located with a 1.25 mmcenter-to-center distance between pins, and protruded 0.4 mm above thesurface of the plate. The entire embossing pattern measures 4 mm×71 mm.The die was heated in a forced air oven at 160° C. oven for 30 minutesprior to use.

Favor 870 superabsorbent polymer (SAP) was sieved to remove particleslarger than 300 micrometers. A 60 mm×120 mm swatch of conventionalcellulose tissue (27 gsm) was evenly sprinkled with the SAP at adistribution of 20 gsm. A second sheet of cellulose tissue was thenplaced over the SAP. Six samples were prepared using this method. Thetissue/SAP/tissue combination was placed on a polytetrafluoroethylene(PTFE) coated surface.

Three samples were treated as follows, employing a method consistentwith that of the Tokuyama patent:

(a) The die was removed from the oven and pressed into thetissue/SAP/tissue combination using a force of 400 Newtons (N) for onesecond. This force is equivalent to the weight applied by 5.7 kg percentimeter of length of the embossing pattern. This procedure wasrepeated 3 times.

The remaining three samples were treated in the following manner,employing a pressure which exceeded the pressure given in Tokuyama:

(b) The die was removed from the oven and pressed into thetissue/SAP/tissue combination using a force of 20,000N for one second.This force is equivalent to the weight applied by 290 kg per centimeterof length of the embossing pattern. This procedure was repeated 3 times.

Results

Using both pressing procedures, the resultant composite was very weaklybonded.

Following procedure (a), the bonds were so fragile that the compositecould not be lifted off the PTFE surface without delaminating. The massof one ply of tissue plus the superabsorbent was 0.34 g. Thegravitational force tending to delaminate the sample as it was liftedoff the PTFE sheet was 0.03N.

Following procedure (b), the bonds were marginally stronger, but thecomposite could not be mounted in the jaws of the test apparatus withoutdelaminating. The delamination strength was not more than 0.3N.

Conclusion

Samples prepared in a manner consistent with "Example 1" of Tokuyama(U.S. Pat. No. 4,414,255) resulted in very weakly bonded composites;with dry peel strength substantially less than is desired for theinvention.

EXAMPLES 23-91 Sample Preparation Procedure

A vacuum box 236 was prepared with a multiplicity of holes 238 formed onthe top member 240 and arranged as representatively shown in FIG. 11.Each elongate slot 238 measured approximately 25 mm×12 mm. The overallpattern measured 260 mm×87 mm. The longer dimension of the slots werealigned along the length of the sample, and the length of samplecorresponds to the length 90 of the article in which the sample could beincorporated. Along the length dimension of the pattern, the roundedends of the immediately adjacent slots were spaced apart by a distanceof 6-7 mm, and along the width of the sample, the straight sides of theimmediately adjacent slots were spaced apart by a distance of 6-7 mm.

Samples were prepared by placing a first carrier sheet onto the vacuumbox. Three types of substrates, i.e., carrier sheet layers, were used:10 gsm, Hydrofil® meltblown; 111 gsm hydro-entangled pulp made withKimberly-Clark Corp., Long Lac 19 northern softwood pulp; and 23 gsmcellulosic forming tissue. Hydrofil® is a hydrophilic amide-cooethyleneoxide copolymer material available from Allied-Signal Corporation abusiness having offices in Morristown, New Jersey. The carrier sheetswere cut into 127 mm×305 mm rectangles, with the machine direction ofthe tissue or non-woven being the same as the long direction of therectangle; additionally, the forming tissue was cut in the cross machinedirection, giving a total of four carrier sheets.

The vacuum was turned on, and 5 grams of SAP (superabsorbent polymer)were uniformly dispersed onto a first carrier sheet. Favor 870polyacrylate SAP was used for this experiment. Using a small brush,superabsorbent was swept into the areas of the first carrier sheet overthe hole regions.

Adhesive was sprayed onto the superabsorbent/carrier composite. Theadhesives included National Starch and Chemical Company 34-5541 (hotmelt construction adhesive), 70-3998 (Cycloflex, hot melt watersensitive adhesive), and 33-2058 (poly vinyl acetate emulsion adhesive)were used. The hot melt adhesives were applied using a hand operatedspray gun, such as a PAM 600 Spraymatic spray gun available fromFastening Technology, Inc., a business located at Charlotte, NorthCarolina. The emulsion adhesive was diluted to 10% solids (by weight)and applied with a hand-powered spray bottle. The dry mass of adhesivewas 0.8±0.3 grams. A second carrier sheet, of the same type as thefirst, was placed over the adhesive, and then pressed into place byrolling a cylinder across the surface. The cylinder weighed about 1 kgand was 5 cm in diameter and 5 cm in length.

In some cases where it was difficult to delaminate a sufficient lengthof the composite to place in the Sintech's jaws, a hot air gun was usedto warm the end of the composite and loosen the bonds sufficiently tohave enough material for the jaws to grab. For some samples a few dropsof water effectively opened the ends of the sheets, the ends of thesecomposites were then dried with the hot air gun before testing. Allsamples which required the use of a hot air gun were allowed to cool toroom temperature before testing.

In the following tables and charts, the terms listed below have thefollowing meanings:

"Hydrofil"--carrier layers composed of meltblown nonwoven fabricconstructed with Hydrofil copolymer and having a basis weight of 10 gsm.

"Machine"--carrier layers composed of cellulose tissue; sample tested inthe machine-direction with the length of the sample oriented in thedirection in which the tissue was manufactured.

"Cross"--carrier layers composed of cellulose tissue; sample tested inthe cross-machine direction with the length of the test sample orientedat right angles to the direction in which the tissue was manufactured.

HEP--carrier layers composed of hydroentangled pulp, as describedherein.

EXAMPLES 23-45

    ______________________________________                                        Peel Testing Results for Samples Bonded with 70-3998:                                                       Force                                                                         per unit                                                       Con-    Force, width, Mode of                                  Sample                                                                              Carrier  dition  Newtons                                                                              N/cm   Failure                                  ______________________________________                                        23    Hydrofil dry     2.10   0.207  Tear.                                    24    Hydrofil water   1.16   0.114  Tear.                                    25    Machine  dry     5.93   0.584  Tear.                                    26    Machine  dry     4.00   0.394  Tear.                                    27    Machine  dry     5.69   0.560  Tear.                                    28    Machine  dry     7.12   0.701  Tear.                                    29    Machine  water   0.69   0.068  Delamination,                                                                 NO tearing.                              30    Machine  water   0.88   0.087  Delamination,                                                                 slight tearing.                          31    Machine  water   1.37   0.135  Delamination,                                                                 slight tearing.                          32    Machine  water   1.33   0.131  Delamination,                                                                 slight tearing.                          33    Cross    dry     1.38   0.136  Tear.                                    34    Cross    dry     4.76   0.469  Tear.                                    35    Cross    dry     2.93   0.288  Tear.                                    36    Cross    water   0.98   0.096  Delamination,                                                                 NO tearing.                              37    Cross    water   0.49   0.048  Delamination,                                                                 NO tearing.                              38    Cross    water   0.55   0.054  Delamination,                                                                 NO tearing.                              39    HEP      dry     9.83   0.968  Delamination,                                                                 NO tearing.                              40    HEP      dry     3.09   0.304  Delamination,                                                                 NO tearing.                              41    HEP      dry     8.34   0.821  Delamination,                                                                 NO tearing.                              42    HEP      dry     2.09   0.206  Delamination,                                                                 NO tearing.                              43    HEP      water   2.20   0.217  Delamination,                                                                 NO tearing.                              44    HEP      water   1.85   0.182  Delamination,                                                                 NO tearing.                              45    HEP      water   3.84   0.378  Delamination,                                                                 NO tearing.                              ______________________________________                                    

Conclusions Based on 70-3988 Results

Samples prepared with 70-3998 (Cycloflex) adhesive varied in their wetand dry bond strengths according to the substrates used for testing.

The Hydrofil meltblown composite, Example 23, had sufficient drystrength. When wet, the carrier sheet of Example 24 was too weakrelative to the bond strength of the adhesive so the composite torerather than delaminated. Example 24 is not representative of theinvention.

The composites of Examples 26-28, 33-35 and 39-42 all had sufficient drystrength for the subject invention. Examples 29, 36-38 and 43-45 are allexemplary of the invention. They had sufficient wet strength, yetdelaminated without tearing. Examples 30-32 had sufficient wet strength,but exhibited some tearing of the wet carrier sheets. Accordingly,Examples 30-32 were marginally representative of the invention. It isbelieved that the examples had localized regions of high adhesive add-onor had localized regions of weakness in the carrier sheets.

The tissue based composites, tested both MD and CD, demonstrate thedesired characteristics of the invention. That is, the bond wassufficiently strong when dry to hold the superabsorbent in place;however, when wet the bonds released. This will allow the superabsorbentto swell without rupturing the carrier.

The hydroentangled pulp sheets were sufficiently stronger than theadhesives, so that the dry composites delaminated rather than tore. Byitself, this is acceptable.

A determination of a maximum wet delamination strength of the compositeis ordinarily not required. The most desirable superabsorbents for thisapplication have significant ability to swell against 0.9 psi (6.2 kPa).In the peel tests, a 10.2 cm wide sample was delaminated. The length ofthe composite being stressed at any given time was about 0.5 cm. The 6.2kPa pressure applied to an area of 0.0005 m² (10 cm×0.5 cm) yields aforce of 3.1N, or 0.3N/cm across the width of the bond. This providesone estimate of an upper, acceptable wet delamination strength of thecomposite.

EXAMPLES 46-77

    ______________________________________                                        Peel Testing Results for Samples Bonded with 34-5541:                                                       Force                                                                         per unit                                                       Con-    Force  width  Mode of                                  Sample                                                                              Carrier  dition  Newtons                                                                              N/cm   Failure                                  ______________________________________                                        46    Machine  dry     9.40   0.927  Tear.                                    47    Machine  dry     16.62  1.636  Tear.                                    48    Machine  dry     12.06  1.187  Tear.                                    49    Machine  dry     15.70  1.545  Tear.                                    50    Machine  water   5.86   0.577  Initially slight                                                              tearing, then                                                                 delamination.                            51    Machine  water   21.59  2.125  Tear.                                    52    Machine  water   2.92   0.287  Delamination,                                                                 slight tearing.                          53    Machine  water   1.72   0.169  Delamination,                                                                 slight tearing                                                                at edge.                                 54    Machine  water   0.51   0.050  Some delami-                                                                  nation, also                                                                  tissue DID tear.                         55    Machine  water   1.07   0.105  Some delami-                                                                  nation, also                                                                  tissue DID tear.                         56    Machine  water   0.66   0.065  Some delami-                                                                  nation, also                                                                  tissue DID tear.                         57    Machine  water   0.88   0.087  Delamination,                                                                 NO tearing.                              58    Machine  saline  0.55   0.054  Delamination,                                                                 NO tearing.                              59    Machine  saline  1.03   0.101  Some delami-                                                                  nation, also                                                                  tissue DID tear.                         60    Machine  saline  0.78   0.077  Some delami-                                                                  nation, also                                                                  tissue DID tear.                         61    Machine  saline  0.54   0.053  Delamination,                                                                 NO tearing                               62    Cross    dry     12.60  1.240  Tear.                                    63    Cross    dry     3.85   0.038  Tear.                                    64    Cross    dry     2.48   0.244  Tear.                                    65    Cross    dry     3.60   0.354  Tear.                                    66    Cross    water   5.58   0.549  Tissue tore                                                                   immediately                                                                   at tape line.                            67    Cross    water   0.96   0.094  Tissue tore                                                                   imediately                                                                    at tape line.                            68    Cross    water   2.56   2.252  Tear.                                    69    Cross    water   1.38   0.136  Tear.                                    70    HEP      dry     13.55  1.334  Delamination,                                                                 NO tearing.                              71    HEP      dry     10.57  1.040  Delamination,                                                                 NO tearing.                              72    HEP      dry     6.28   0.618  Delamination,                                                                 NO tearing.                              73    HEP      dry     8.11   0.798  Delamination                                                                  within HEP                                                                    sheet.                                   74    HEP      water   2.08   0.205  Delamination,                                                                 NO tearing.                              75    HEP      water   2.55   0.251  Delamination,                                                                 NO tearing,                                                                   one corner of                                                                 the samples                                                                   slipped out                                                                   of upper jaw.                            76    HEP      water   9.62   0.947  Tore from                                                                     edge.                                    77    HEP      water   7.65   0.753  Delamination,                                                                 NO tearing.                              ______________________________________                                    

Conclusions Based on 34-5541 Results

Samples prepared with 34-5541, a hydrophobic hot melt adhesive varied intheir wet and dry bond strengths according to the substrates used fortesting. In general, the samples had less wet strength than drystrength. Despite the hydrophobic nature of the adhesive, this is to beexpected because the carriers are typically weaker when wet. Consideringthe composites made with tissue in the machine direction, Examples 46-49exhibited sufficient dry strength. Examples 57, 58 and 61 were allexemplary of the invention. They had sufficient wet strength, yetdelaminated without tearing. Example 51 tore when wet, and wasunacceptable. Examples 52-56, 59 and 60 all had sufficient wet strength,but exhibited some tearing of the wet carrier sheets. Accordingly, theselatter examples were marginally representative of the invention. It isbelieved that the examples had localized regions of high adhesive add-onor had localized regions of weakness in the carrier sheets.

Considering the composites made with tissue in the cross direction,Examples 62-65 exhibited sufficient dry strength. Examples 66-69 torewhen wet, and are not representative of the invention.

Considering the Examples made with HEP, Examples 70-73 exhibitedsufficient dry strength. Examples 74, 75 and 77 are all exemplary of theinvention; they had sufficient wet strength and delaminated withouttearing. Example 76 had sufficient wet strength, but exhibited sometearing of the wet carrier sheets. Accordingly, these latter exampleswere marginally representative of the invention. It is believed that theexamples may have been skewed in the jaws of the testing apparatus.

EXAMPLES 78-91

    ______________________________________                                        Peel Testing Results for Samples Bonded with 33-2058:                                                       Force                                                                         per unit                                                       Con-    Force  width  Mode of                                  Sample                                                                              Carrier  dition  Newtons                                                                              N/cm   Failure                                  ______________________________________                                        78    HEP      dry     1.21   0.119  Delamination,                                                                 NO tearing.                              79    HEP      dry     0.35   0.034  Delamination,                                                                 NO tearing.                              80    HEP      dry     0.17   0.017  Delamination,                                                                 NO tearing.                              81    HEP      dry     1.00   0.098  Delamination,                                                                 NO tearing.                              82    HEP      water   0.46   0.045  Delamination,                                                                 NO tearing.                              83    HEP      water   0.30   0.030  Delamination,                                                                 NO tearing.                              84    HEP      water   0.29   0.029  Delamination,                                                                 NO tearing.                              85    HEP      water   0.56   0.055  Delamination,                                                                 NO tearing.                              86    Machine  dry     3.23   0.318  Tear.                                    87    Machine  dry     3.02   0.297  Tear.                                    88    Machine  dry     1.97   0.194  Tear.                                    89    Machine  water   1.46   0.144  Delamination,                                                                 slight tearing.                          90    Machine  water   1.09   0.107  Delamination,                                                                 NO tearing.                              91    Machine  water   2.75   0.271  Delamination,                                                                 slight tearing.                          ______________________________________                                    

Conclusions Based on 33-2058 Results

Samples prepared with 33-2058 (poly vinyl acetate emulsion) adhesivevaried in their wet and dry bond strengths according to the substratesused for testing. Additionally, significant variability in bond strengthwas observed among composites of the same composition. Among thecomposites made with the poly vinyl acetate emulsion, samples 78, 81,82, 85, 86, 87, 88, 89, 90 and 91 exemplify the subject invention.Samples 79 and 80 had insufficient dry strength, while samples 83 and 84had insufficient wet strength to be representative of the invention.

EXAMPLES 92-107

A suitable technique for determining the saturated free-swell volume ofthe high absorbency material within the absorbent laminate is thefollowing Free-Swell procedure:

Five grams of high-absorbency material are sealed in a pouch which issufficiently large that it will not inhibit the expansion of thecontained and wetted high-absorbency material. The pouch material is acellulose tissue having a basis weight of 21 gsm, has a wet strengthwhich is sufficiently high to perform the test, and is porous to liquid.The pouch material substantially prevents the migration of thehigh-absorbency material out from the pouch, whether the high absorbencymaterial is wet or dry. The cellulose tissue of the pouch is sealed atthe edges with a bead of conventional, hot melt construction adhesive.The pouch containing the unrestrained high absorbency material isallowed to swell in an excess of a 0.85% saline solution for 15 minutes.The pouch containing the swollen high absorbency material is thenpressed for 2.25 minutes under a pressure of 3.45 kPa and allowed todrain. The free swell capacity of the high absorbency material is thetotal grams of saline retained minus the wet weight of the pouchmaterial, minus the dry weight of the high absorbency material, and thendivided by the original dry weight (five grams) of the high absorbencymaterial placed in the pouch (Free Swell value).

A technique for determining the saturated, expansion swelling of thehigh-absorbency material within an absorbent laminate is the followingLaminate-Swell procedure:

The composite forming the absorbent laminate is sealed in a pouch, asdescribed in the Free-Swell procedure. The pouch and absorbent compositecontained therewithin are allowed to swell in excess 0.85% salinesolution for 15 minutes. After the swelling period, the pouch and itscontents are removed from the saline, placed under a pressure of 3.45kPa and allowed to drain. The pouch is weighed to determine the totalamount of fluid absorbed. The wet weight of the pouch, the wet weight ofthe absorbent laminate components (excluding the high absorbencymaterial), and the dry weight of the high absorbency material aresubtracted from the total wet weight of the combined pouch and containedabsorbent laminate so that only the weight of the liquid contained bythe high absorbency material is determined. The weight of liquidcontained by the high absorbency material divided by the dry weight ofthe high absorbency material is the swelling capacity of the highabsorbency material when assembled into the absorbent laminate (LaminateSwell value).

The wet weight of the pouch (Free-Swell procedure), or of the pouchcontaining all of the absorbent laminate components excluding the highabsorbency material (Laminate Swell procedure) are determined by thesame soaking procedure as described in those procedures (15 minute soaktime followed by a drainage period of 2.25 minutes under an applied loadof 3.45 kPa). The wet weights of these materials are used as tareweights in the calculation to determine the liquid contained by the highabsorbency material.

Once all of the measurements have been taken in the Laminate Swellprocedure, the pouch is carefully opened to examine the absorbentlaminate. The absorbent laminate is examined and the number of pocketswhich ruptured (migrated superabsorbent due to the bursting of one ofthe absorbent laminate carrier layers) is recorded and expressed as apercentage of the total number of pockets in the absorbent laminatepattern.

The constriction of the swelling and absorption capacity of apolyacrylate superabsorbent material was determined for the followingsamples. The superabsorbent material was Favor SAB 870 available fromStockhausen, Inc., a business having offices in Greensboro, NorthCarolina. The absorbent laminate composites were prepared in accordancewith the preparation procedure described for Examples 23-91 except that17 gsm and 21 gsm cellulose tissues were used as the first carrier layertissue and the sealing tissue respectively. The adhesive used inExamples 98-102 was Cycloflex 70-3998 (a hot melt, water sensitiveadhesive) applied in a sprayed pattern at an add-on level of about 75gsm. The adhesive used in Examples 103-107 was National Starch 34-5541hot melt construction adhesive applied in a spray pattern at an add-onlevel of about 33 gsm. The samples prepared with the 34-5541 adhesivewere annealed in a 60° C. convection oven for two minutes prior totesting to provide a good seal between the tissue layers.

    __________________________________________________________________________    Absorbent Capacity Data                                                       Example                                                                            Adhesive                                                                           SAP Capacity                                                                          % Capacity                                                                          % Capacity Delaminated                                No.  System                                                                             (gm/gm) Change A                                                                            Change B                                                                            % Torn                                                                             (yes/no)                                   __________________________________________________________________________     92  None 29.1    --    -7.6  --   --                                          93  None 26.5    --    -15.9 --   --                                          94  None 25.6    --    -18.7 --   --                                          95  None 28.4    --    -9.8  --   --                                          96  None 29.4    --    -6.7  --   --                                          97  None 29.1    --    -7.6  --   --                                          98  70-3998                                                                            31.8    13.5  --    0    yes                                         99  70-3998                                                                            32.1    14.5  --    0    yes                                        100  70-3998                                                                            31.1    11.0  --    0    yes                                        101  70-3998                                                                            30.9    10.3  --    0    yes                                        102  70-3998                                                                            31.7    13.4  --    0    yes                                        103  34-5541                                                                            26.7    -4.5  -15.2 18.4 no                                         104  34-5541                                                                            28.0    -0.1  -11.1 10.5 no                                         105  34-5541                                                                            24.4    -12.8 - 22.5                                                                              28.9 no                                         106  34-5541                                                                            26.7    -4.5  -15.2 36.8 no                                         107  34-5541                                                                            26.9    -4.0  -14.7 42.1 no                                         __________________________________________________________________________     SAP = superabsorbent polymer                                                  % Capacity Change A = determined with respect to the average of the SAP       capacities of Examples 92-97 (FreeSwell).                                     % Capacity Change B = determined with respect to the average of the SAP       capacities of Examples 98-102.                                                % Torn = Percentage of pocket regions in the laminate sample that had         tears at least 3 mm in length.                                                gm/gm = grams of liquid absorbed per gram of SAP.                        

Examples 98-102 demonstrate the benefit of having the carrier layersdelaminate to avoid excessive movement and excessive restriction ofswelling of the high absorbency material contained within the discretepockets.

Example Sets C, T, B and P

The Examples of Sample set C were prepared on the same vacuum box thatwas used to prepare Examples 23-91. A 17 gsm basis weight cellulosetissue was placed on the vacuum box. Then, 7 grams of Favor 870superabsorbent were evenly distributed and brushed into the pocketsformed in the cellulose tissue by the vacuum. Approximately 23 gsm ofNational Starch & Chemical Company Cycloflex 70-3998 adhesive weresprayed onto the tissue and superabsorbent using the PAM 600 SpraymaticSpray Gun set at 330° F. A second, 21 gsm cellulose tissue was thenplaced on top of the first tissue and the pocket sections ofsuperabsorbent particles, and the spaces between and around the pocketswere pressed by hand to obtain intimate contact between the tissuelayers and the adhesive. The laminate structure was then trimmed to 140mm×292 mm with a hand paper cutter.

The Examples of Sample set P were made with the same technique employedto produce the Examples of Sample set C except; a 102 mm×267 mm "windowframe" template was placed over the first tissue to surround the area ofthe desired pocket array and to allow the Cycloflex adhesive to contactonly the area inside the open "window" region of the template. Afterremoving the template, the second tissue was superposed and applied ontothe first tissue layer and the pockets of superabsorbent particles.Before removing the laminate from the vacuum box, the second tissuelayer was folded back and approximately 23 gsm of National Starch andChemical Company's 34-5541 adhesive was sprayed on the exposed edgeusing a second PAM 600 Spraymatic Spray Gun also set at 330° F. Thefolded back tissue was then unfolded and hand pressed into the adhesiveto form the Secondary Attachment Means.

The Examples of Sample set B were made with the same technique employedto produce the Examples of Sample set P except; a 0.5-3 mm width line of34-5541 adhesive was applied about 6 mm away from the edge of the pocketarray on the exposed edge produced by folding back the second tissuelayer. The adhesive line replaced the 23 gsm of sprayed adhesiveemployed for Sample set P.

The Examples of Sample set T were made with the same technique employedto produce the Examples of Sample set C except; 10 holes were blankedoff to make a pocket array area of 87 mm×180 mm. 5.2 grams of thesuperabsorbent was used. 10 gsm Hydrofil® meltblown was used in place ofeach layer of cellulose tissue. The laminate was trimmed to measure 140mm×230 mm and was heat fused with a hand heat sealer 25 mm wide aroundthe entire pocket array. The heat fused area was about 2 mm from thenearest pocket.

Gel Containment Test Method

To determine the ability of the secondary attachments to contain thesuperabsorbent, samples were soaked in excess (i.e. enough to submergethe samples) 0.85 weight percent saline for five minutes. Each samplewas then lifted out of the saline on an open mesh polyolefin screen,shaken slightly to remove some of the excess liquid, placed on a labbench and covered with a rigid piece of 152 mm×305 mm Plexiglass (i.e.of greater size than the pocket region 144). Weights were then placed onthe Plexiglass to provide a uniformly distributed total pressure of 6.7KPa (i.e. less weight was used for sample T since it was not as long).After five minutes, the weights and plexiglass were carefully removed.The total perimeter length of the secondary attachments was measured inmillimeters.

Also measured was the length (in millimeters) of the portions of thesecondary attachments along which exposed (escaped) superabsorbent wasvisible. The percentage of "open" perimeter was calculated by dividingthe length of exposed superabsorbent by the total perimeter length ofthe secondary attachment means, and then multiplying the quotient by100. The calculated percentage represents the Peripheral Release value.

Additional samples were made in accordance with procedures describedabove, except that the pockets of superabsorbent were eliminated. Thesecondary attachments were formed just by applying adhesive or by heatsealing to interconnect the two tissue layers. The resultant "lines" ofattachment were then tested using the Delamination Testing Procedure(wet) described above. The results are summarized in the followingtable.

    ______________________________________                                        Sample                                                                              % of Opened Sample  Peak Wet Peel Strength of                           I.D.  Attachment  I.D.    Secondary Attachments, N/cm                         ______________________________________                                        C-1   16.2        C-12    0.086                                               2      8.8        13      0.086                                               3     12.4        14      0.086                                               4      7.5        15      0.089                                               5      9.4        16      0.085                                               6     11.8        17      0.129                                               7     13.2        18      0.093                                               8     21.0        19      0.078                                               9      5.0        20      0.077                                               10     0.0        21      0.053                                               11     8.0                                                                          avg = 10.3          avg = 0.086                                         T-1   0           T-7     0.282                                               2     0            8      0.373                                               3     0            9      0.144                                               4     0           10      0.057                                               5     0           11      0.110                                               6     0           12      0.132                                                     avg = 0             avg = 0.186                                         B-1   0           B-7     0.195                                               2     0            8      0.230                                               3     0            9      0.210                                               4      3.8        10      0.220                                               5     0           11      0.202                                               6     0           12      0.196                                                                 13      0.232                                                     avg = 0.6   14      0.146                                                                 15      0.197                                                                 16      0.211                                                                         avg = 0.213                                         P-1   0           P-7     0.060                                               2     0            8      0.170                                               3     0            9      0.181                                               4     0           10      0.124                                               5     0           11      0.102                                               6     0           12      0.181                                                                 13      0.147                                                     avg = 0     14      0.124                                                                 15      0.101                                                                 16      0.124                                                                         avg = 0.134                                         ______________________________________                                    

These results indicate that the secondary attachments in Sample set Cwere not consistently acceptable. Samples T, B and P were consistentlyacceptable and are representative of the invention. These sample setsindicate the improved containment resulting from the higher Peak WetPeel Strengths.

Having thus described the invention in rather full detail, it will bereadily apparent that various changes and modifications may be madewithout departing from the spirit of the invention. All of such changesand modifications are contemplated as being within the scope of thepresent invention, as defined by the subjoined claims.

We claim:
 1. An absorbent article, comprising:a first, liquid-permeablecarrier layer and at least a second carrier layer; water-sensitiveattaching means for securing together said carrier layers atsubstantially attached first zones thereof, said carrier layers havingsubstantially unattached zones providing a plurality of pocket regionswith said substantially attached first zones located between said pocketregions; high-absorbency material located within said pocket regions toprovide an absorbent laminate; and secondary attaching means forsecuring together said carrier layers along selected secondaryattachment regions and providing a substantially water-insensitiveconnection therebetween, said secondary attachment regions substantiallyrestricted to locations spaced from said pocket regions; wherein, saidwater-sensitive attachment means in said substantially attached firstzones provides a wet strength adequate to hold said carrier layerstogether when wet, and wherein said wet strength is less than aseparating force imparted by a swelling of said high-absorbency materialwhen said high-absorbency material is exposed to an aqueous liquid. 2.An absorbent article as recited in claim 1, wherein said secondaryattaching means is substantially restricted to an outer periphery ofsaid absorbent laminate.
 3. An absorbent article as recited in claim 1,wherein said secondary attaching means is substantially restricted to anouter periphery of said absorbent laminate and interstitial locationsbetween immediately adjacent pocket regions.
 4. An absorbent article, asrecited in claim 1, wherein said water-sensitive attachment means isconfigured to release at an applied load which is less than a loadneeded to delaminate said attachment means without excessively tearingat least one of said carrier layers when said carrier layers are wettedwith an aqueous liquid.
 5. An absorbent article, as recited in claim 1,wherein said water-sensitive attachment means provides a wet bondstrength of not less than about 0.04N/cm.
 6. An absorbent article, asrecited in claim 5, wherein said water-sensitive attachment meansprovides a wet bond strength of not more than about 5N/cm.
 7. Anabsorbent article, as recited in claim 1, wherein said water-sensitiveattaching means provides a dry bond strength of at least about 0.05N/cm.8. An absorbent article, as recited in claim 1, wherein said firstcarrier layer has a burst strength of at least about 0.08N/cm.
 9. Anabsorbent article, as recited in claim 8, wherein said second carrierlayer has a burst strength of at least about 0.08N/cm.
 10. An absorbentarticle, as recited in claim 9, wherein said first carrier layercomprises a wettable fibrous web.
 11. An absorbent article, as recitedin claim 10, wherein said second carrier layer is liquid permeable andcomprises a wettable, fibrous web.
 12. An absorbent article, as recitedin claim 11, wherein at least one of said carrier layers is a web whichincludes meltblown fibers and wherein said meltblown web is configuredto provide water-sensitivity to said water-sensitive attaching means.13. An absorbent article, as recited in claim 11, wherein at least oneof said carrier layers is a high wet-strength tissue composed ofcellulosic fibers.
 14. An absorbent article as recited in claim 1,wherein said secondary attaching means includes lines of substantiallywater-insensitive attachment, said attachment lines having a widthdimension of not more than about 3 cm.
 15. An absorbent article asrecited in claim 14, wherein said secondary attaching means includeslines of substantially water-insoluble adhesive.
 16. An absorbentarticle as recited in claim 14, wherein said secondary attaching meansincludes lines of thermal bonds.
 17. An absorbent article as recited inclaim 14, wherein said water-sensitive attachment means provides a wetbond strength of not less than about 0.07N/cm.
 18. An absorbent articleas recited in claim 14, wherein said water-sensitive attachment meansprovides a wet bond strength of not less than about 0.09N/cm.
 19. Anabsorbent article as recited in claim 18, wherein said water-sensitiveattachment means provides a wet bond strength of not more than about2N/cm.
 20. An absorbent article as recited in claim 18, wherein saidwater-sensitive attachment means provides a wet bond strength of notmore than about 1N/cm.
 21. An absorbent article, as recited in claim 1,wherein said pocket regions are spaced apart from one another by adistance of not less than about 0.15 cm.
 22. An absorbent article, asrecited in claim 21, wherein immediately adjacent pocket regions arespaced apart from each other by a distance of not more than about 3 cm.23. An absorbent article, as recited in claim 22, further comprising asurge management layer positioned generally adjacent a major bodysidesurface of said absorbent laminate.
 24. An absorbent article, as recitedin claim 23, wherein said surge management layer is composed of anonwoven fibrous web composed of synthetic fibers and having a basisweight within the range of about 24-300 gsm.
 25. An absorbent article,as recited in claim 23, further comprising a distribution layerpositioned next to a major outer side surface of said absorbentlaminate.
 26. An absorbent article, as recited in claim 23, wherein saiddistribution layer has a length which is within the range of about75-175% of a corresponding length of said absorbent laminate.
 27. Anabsorbent article, as recited in claim 26, wherein said distributionlayer has a width which is within the range of about 75-175% of acorresponding width of said absorbent laminate.